Three-dimensional super-resolution microscopy of the inactive X chromosome territory reveals a collapse of its active nuclear compartment harboring distinct Xist RNA foci.
Three-dimensional super-resolution microscopy of the inactive X chromosome territory reveals a collapse of its active nuclear compartment harboring distinct Xist RNA foci.
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DOI：
10.1186/1756-8935-7-8
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发表时间：
2014
影响因子：
3.9
通讯作者：
Cremer M
中科院分区：
文献类型：
--
作者：
Smeets D;Markaki Y;Schmid VJ;Kraus F;Tattermusch A;Cerase A;Sterr M;Fiedler S;Demmerle J;Popken J;Leonhardt H;Brockdorff N;Cremer T;Schermelleh L;Cremer M
Xist RNA修饰的巴尔体是雌性哺乳动物中致密的非活性X区域的结构标志。利用超分辨三维结构照明显微镜（3D-SIM）和定量图像分析技术，比较了人和小鼠体细胞中Barr体的超微结构与活性染色体区域（CTs）的差异，探讨了小鼠胚胎干细胞（ESCs）早期分化失活时Barr体形成的时空过程。我们证明，所有的CT是由结构相连的染色质结构域簇（CDC）。在活动性CT中，CDC的外周含有富含转录活性标记的低密度染色质，称为染色质周区（PR）。PR与一个连续的通道系统（染色质间室（IC））接壤，该通道系统始于核孔并遍布CT。我们提出，PR和IC通道中的大分子复合物一起形成转录允许的活性核室（ANC）。巴尔体与活动性CT的不同之处在于部分塌陷的ANC与CDC之间的距离明显更近，尽管维持了与核孔连接的基本IC通道系统。不同的Xist RNA灶，紧密相邻的核基质支架附着因子-A（SAF-A）定位在整个Xi沿着基本的ANC。在早期分化的ESCs初始Xist RNA扩散之前巴尔体形成，这与随后的RNA聚合酶II（RNAP II）的排除同时发生。在雄性ESC中诱导转基因常染色体Xist RNA触发“常染色体巴尔体”的形成，该体具有较少压实的染色质和不完全的RNAP II排斥。3D-SIM为转录活性CT和巴尔体的功能结构之间的深刻差异提供了实验证据。然而，CT组织的基本结构特征，如CDC和IC通道，仍然是公认的，反对巴尔体在核小体水平上的均匀压实。在基本ANC的边界处的不同Xist RNA病灶的定位可以被认为是与沉默基因的动态相互作用的快照。富集的SAF-A内Xi领土和其密切的空间关联Xist RNA表明它们的合作功能的结构组织的Xi。
A Xist RNA decorated Barr body is the structural hallmark of the compacted inactive X territory in female mammals. Using super-resolution three-dimensional structured illumination microscopy (3D-SIM) and quantitative image analysis, we compared its ultrastructure with active chromosome territories (CTs) in human and mouse somatic cells, and explored the spatio-temporal process of Barr body formation at onset of inactivation in early differentiating mouse embryonic stem cells (ESCs). We demonstrate that all CTs are composed of structurally linked chromatin domain clusters (CDCs). In active CTs the periphery of CDCs harbors low-density chromatin enriched with transcriptionally competent markers, called the perichromatin region (PR). The PR borders on a contiguous channel system, the interchromatin compartment (IC), which starts at nuclear pores and pervades CTs. We propose that the PR and macromolecular complexes in IC channels together form the transcriptionally permissive active nuclear compartment (ANC). The Barr body differs from active CTs by a partially collapsed ANC with CDCs coming significantly closer together, although a rudimentary IC channel system connected to nuclear pores is maintained. Distinct Xist RNA foci, closely adjacent to the nuclear matrix scaffold attachment factor-A (SAF-A) localize throughout Xi along the rudimentary ANC. In early differentiating ESCs initial Xist RNA spreading precedes Barr body formation, which occurs concurrent with the subsequent exclusion of RNA polymerase II (RNAP II). Induction of a transgenic autosomal Xist RNA in a male ESC triggers the formation of an ‘autosomal Barr body’ with less compacted chromatin and incomplete RNAP II exclusion. 3D-SIM provides experimental evidence for profound differences between the functional architecture of transcriptionally active CTs and the Barr body. Basic structural features of CT organization such as CDCs and IC channels are however still recognized, arguing against a uniform compaction of the Barr body at the nucleosome level. The localization of distinct Xist RNA foci at boundaries of the rudimentary ANC may be considered as snap-shots of a dynamic interaction with silenced genes. Enrichment of SAF-A within Xi territories and its close spatial association with Xist RNA suggests their cooperative function for structural organization of Xi.
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使用超分辨率光显微镜在纳米尺度上测量复制结构。
影响因子：
14.9
作者：
Baddeley D;Chagin VO;Schermelleh L;Martin S;Pombo A;Carlton PM;Gahl A;Domaing P;Birk U;Leonhardt H;Cremer C;Cardoso MC
通讯作者：
Cardoso MC
影响因子：
16
作者：
Chandra, Tamir;Kirschner, Kristina;Thuret, Jean-Yves;Pope, Benjamin D.;Ryba, Tyrone;Newman, Scott;Ahmed, Kashif;Samarajiwa, Shamith A.;Salama, Rafik;Carroll, Thomas;Stark, Rory;Janky, Rekin's;Narita, Masako;Xue, Lixiang;Chicas, Agustin;Nunez, Sabrina;Janknecht, Ralf;Hayashi-Takanaka, Yoko;Wilson, Michael D.;Marshall, Aileen;Odom, Duncan T.;Babu, M. Madan;Bazett-Jones, David P.;Tavare, Simon;Edwards, Paul A. W.;Lowe, Scott W.;Kimura, Hiroshi;Gilbert, David M.;Narita, Masashi
通讯作者：
Narita, Masashi
影响因子：
16.6
作者：
Casas-Delucchi, Corella S.;Brero, Alessandro;Cardoso, M. Cristina
通讯作者：
Cardoso, M. Cristina
DOI：
10.1101/sqb.1993.058.01.085
发表时间：
1993-01-01
期刊：
COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY
影响因子：
--
作者：
CREMER, T;KURZ, A;LICHTER, P
通讯作者：
LICHTER, P
DOI：
10.1073/pnas.0408021101
发表时间：
2004-12-14
影响因子：
11.1
作者：
Chadwick, BP;Willard, HF
通讯作者：
Willard, HF