Comprehensive DNA Methylation Analysis of Retrotransposons in Male Germ Cells
Comprehensive DNA Methylation Analysis of Retrotransposons in Male Germ Cells
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DOI：
10.1016/j.celrep.2015.07.060
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发表时间：
2015-09-08
期刊：
影响因子：
8.8
通讯作者：
Nakano, Toru
中科院分区：
文献类型：
--
作者：
Nagamori, Ippei;Kobayashi, Hisato;Nakano, Toru
逆转录转座子的从头DNA甲基化对于沉默至关重要。在这里，我们使用DNA甲基化分析来检查小鼠雄性生殖细胞中的反转录转座子。长散布核元件（LINE）的DNA甲基化依赖于皮尔纳，并且较年轻的LINE表现出更大的皮尔纳依赖性。相反，大多数长末端重复序列（LTR）逆转录转座子产生较低水平的piRNA，并且不显示显著的皮尔纳依赖性。DNA甲基化和几个LTR反转录转座子的相应皮尔纳表达之间的关系在Mili无效细胞中降低，但在Miwi2无效细胞中不降低。这些观察结果提高了在没有Miwi2的情况下piRNA依赖性DNA甲基化的可能性。因此，逆转录转座子基因沉默的分子机制似乎比以前认为的更复杂。
De novo DNA methylation of retrotransposons is critical for silencing. Here, we use DNA methylation analysis to examine retrotransposons in mouse male germ cells. DNA methylation of long interspersed nuclear elements (LINEs) is dependent on piRNA, and younger LINEs exhibit greater piRNA dependence. In contrast, most long terminal repeat (LTR) retrotransposons produce lower levels of piRNAs and do not show significant piRNA dependence. The relationship between DNA methylation and corresponding piRNA expression of several LTR retrotransposons was reduced in Mili-null cells, but not Miwi2-null cells. These observations raise the possibility of piRNA-dependent DNA methylation without Miwi2. Therefore, it appears that the molecular mechanisms of the gene silencing of retrotransposons are more complicated than previously thought.