One-way control of FWA imprinting in Arabidopsis endosperm by DNA methylation
One-way control of FWA imprinting in Arabidopsis endosperm by DNA methylation
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DOI：
10.1126/science.1089835
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发表时间：
2004-01-23
期刊：
影响因子：
56.9
通讯作者：
Kakutani, T
中科院分区：
文献类型：
--
作者：
Kinoshita, T;Miura, A;Kakutani, T
拟南芥FWA基因最初是从开花晚的表观遗传突变体中鉴定出来的，这些突变体显示异位FWA表达与转录起始位点周围重复序列的遗传低甲基化相关。在这里，我们发现野生型FWA在胚乳中显示印迹（母体起源特异性）表达。FWA印记依赖于维持DNA甲基转移酶MET1，在哺乳动物中也是如此。然而，与哺乳动物不同，FWA印记不是通过等位基因特异性从头甲基化建立的。它是由母体配子体特异性基因激活建立的，这取决于DNA糖基化酶基因DEMETER。由于胚乳对下一代没有贡献，激活的FWA基因不需要再次沉默。双受精使植物能够利用这种“单向”控制胚乳中的印迹和DNA甲基化。
The Arabidopsis FWA gene was initially identified from late-flowering epigenetic mutants that show ectopic FWA expression associated with heritable hypomethylation of repeats around transcription starting sites. Here, we show that wild-type FWA displays imprinted (maternal origin-specific) expression in endosperm. The FWA imprint depends on the maintenance DNA methyltransferase MET1, as is the case in mammals. Unlike mammals, however, the FWA imprint is not established by allele-specific de novo methylation. It is established by maternal gametophyte-specific gene activation, which depends on a DNA glycosylase gene, DEMETER. Because endosperm does not contribute to the next generation, the activated FWA gene need not be silenced again. Double fertilization enables plants to use such "one-way" control of imprinting and DNA methylation in endosperm.