Plant 45S rDNA clusters are fragile sites and their instability is associated with epigenetic alterations.
Plant 45S rDNA clusters are fragile sites and their instability is associated with epigenetic alterations.
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植物 45S rDNA 簇是脆弱位点，其不稳定性与表观遗传改变有关
DOI：
10.1371/journal.pone.0035139
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发表时间：
2012
期刊：
影响因子：
3.7
通讯作者：
Li L
中科院分区：
文献类型：
--
作者：
Huang M;Li H;Zhang L;Gao F;Wang P;Hu Y;Yan S;Zhao L;Zhang Q;Tan J;Liu X;He S;Li L
我们的前期研究表明，45 SrDNA簇是在黑麦草中自发表达的染色体脆性位点。在本研究中，45 S rDNA的脆弱表型在蚜虫菌素（APH）孵育几种植物。进一步的放线菌素D（ActD）处理表明，转录胁迫可能会干扰染色质包装，导致45 S rDNA的脆弱表达。这些数据确定了45 S rDNA位点作为复制依赖性以及转录依赖性的脆性位点在植物中。在ActD的存在下，观察到显着的染色质构象转变为开放的染色质构象，并观察到外部转录间隔区（5′ETS）转录物的不完整5′末端的累积，伴随着DNA甲基化降低，组蛋白H3水平降低，组蛋白乙酰化和H3 K4 me 2水平增加，这表明这些表观遗传学改变与45 S rDNA缩合的失败有关。ActD处理后γ-H2 AX在45 SrDNA位点上的积累表明，DNA损伤信号通路与45 SrDNA脆性表型的出现有关。我们的数据提供了45 S rDNA转录和染色质包装缺陷之间的联系，并为进一步确定所涉及的分子机制打开了大门。
Our previous study demonstrated that 45S ribosomal DNA (45S rDNA) clusters were chromosome fragile sites expressed spontaneously in Lolium. In this study, fragile phenotypes of 45S rDNA were observed under aphidicolin (APH) incubation in several plant species. Further actinomycin D (ActD) treatment showed that transcriptional stress might interfere with chromatin packaging, resulting in 45S rDNA fragile expression. These data identified 45S rDNA sites as replication-dependent as well as transcription-dependent fragile sites in plants. In the presence of ActD, a dramatic switch to an open chromatin conformation and accumulated incomplete 5′ end of the external transcribed spacer (5′ETS) transcripts were observed, accompanied by decreased DNA methylation, decreased levels of histone H3, and increased histone acetylation and levels of H3K4me2, suggesting that these epigenetic alterations are associated with failure of 45S rDNA condensation. Furthermore, the finding that γ-H2AX was accumulated at 45S rDNA sites following ActD treatment suggested that the DNA damage signaling pathway was associated with the appearance of 45S rDNA fragile phenotypes. Our data provide a link between 45S rDNA transcription and chromatin-packaging defects and open the door for further identifying the molecular mechanism involved.
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影响因子：
64.5
作者：
Casper, AM;Nghiem, P;Glover, TW
通讯作者：
Glover, TW
45S rDNA 区域是染色体脆弱位点，在体外表现为黑麦草根尖分生细胞中期染色体上的缺口
影响因子：
3.7
作者：
Huang J;Ma L;Yang F;Fei SZ;Li L
通讯作者：
Li L
影响因子：
21.3
作者：
Chan, Kok Lung;Palmai-Pallag, Timea;Hickson, Ian D.
通讯作者：
Hickson, Ian D.
影响因子：
1.6
作者：
Hanson, RE;IslamFaridi, MN;Price, HJ
通讯作者：
Price, HJ
影响因子：
3.4
作者：
Cazaux B;Catalan J;Veyrunes F;Douzery EJ;Britton-Davidian J
通讯作者：
Britton-Davidian J