Candida albicans repetitive elements display epigenetic diversity and plasticity.
Candida albicans repetitive elements display epigenetic diversity and plasticity.
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DOI：
10.1038/srep22989
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发表时间：
2016-03-14
影响因子：
4.6
通讯作者：
Buscaino A
中科院分区：
文献类型：
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作者：
Freire-Benéitez V;Price RJ;Tarrant D;Berman J;Buscaino A
转录沉默的异染色质与重复DNA有关。异染色质在不同生物体之间是否以及如何存在差异，以及其结构是否可以根据环境信号进行重塑，目前还知之甚少。在这里，我们解决这个问题，通过分析与人类真菌病原体白色念珠菌的DNA重复的染色质状态。我们的分析表明，与模型系统相反，每种类型的重复元件组装成一个不同的染色质状态。经典的Sir2依赖的hypoacetylated和hypomethylated染色质与rDNA基因座相关，而端粒区组装成一个弱的异染色质，只有轻度hypoacetylated和hypomethylated。主要重复序列是一类串联重复序列，它被组装成具有常染色质和异染色质特征的中间染色质状态。标记基因沉默分析和全基因组RNA测序表明，C。白色念珠菌异染色质抑制重复相关编码和非编码RNA的表达。我们发现，端粒异染色质是动态的，重塑后的环境变化。弱异染色质在30 °C时与端粒相关，而强异染色质在39 °C时在这些区域组装，这是一种模拟宿主中度发热的温度。因此在C.在白念珠菌中，差异染色质状态控制基因表达，表观遗传可塑性与适应有关。
Transcriptionally silent heterochromatin is associated with repetitive DNA. It is poorly understood whether and how heterochromatin differs between different organisms and whether its structure can be remodelled in response to environmental signals. Here, we address this question by analysing the chromatin state associated with DNA repeats in the human fungal pathogen Candida albicans. Our analyses indicate that, contrary to model systems, each type of repetitive element is assembled into a distinct chromatin state. Classical Sir2-dependent hypoacetylated and hypomethylated chromatin is associated with the rDNA locus while telomeric regions are assembled into a weak heterochromatin that is only mildly hypoacetylated and hypomethylated. Major Repeat Sequences, a class of tandem repeats, are assembled into an intermediate chromatin state bearing features of both euchromatin and heterochromatin. Marker gene silencing assays and genome-wide RNA sequencing reveals that C. albicans heterochromatin represses expression of repeat-associated coding and non-coding RNAs. We find that telomeric heterochromatin is dynamic and remodelled upon an environmental change. Weak heterochromatin is associated with telomeres at 30 °C, while robust heterochromatin is assembled over these regions at 39 °C, a temperature mimicking moderate fever in the host. Thus in C. albicans, differential chromatin states controls gene expression and epigenetic plasticity is linked to adaptation.