Silencing in sperm cells is directed by RNA movement from the surrounding nurse cell
Silencing in sperm cells is directed by RNA movement from the surrounding nurse cell
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DOI：
10.1038/nplants.2016.30
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发表时间：
2016-04-01
期刊：
影响因子：
18
通讯作者：
Slotkin, R. Keith
中科院分区：
文献类型：
--
作者：
Martinez, German;Panda, Kaushik;Slotkin, R. Keith
植物小干扰RNA(SiRNAs)在细胞间进行通讯，并通过维管系统进行长距离的运输。然而，siRNA进入生殖细胞的研究一直存在争议，这是因为精子细胞周围的终末分化的花粉营养营养细胞经历了程序性异染色质解缩和转座元件(TES)的转录重新激活。TES的转录导致其转录后降解为siRNAs，有人认为这种TE重新激活的目的是产生并装载TES siRNAs到精子细胞中。在这里，我们确定了在花粉粒中产生TE siRNA的分子途径，并证明了由花粉营养细胞转录产生的siRNAs可以沉默精子细胞中的TE报告。我们的数据表明，TE siRNA的作用是非细胞自主的，抑制生殖细胞中的TE活性，并可能抑制下一代的TE活性。
Plant small interfering RNAs (siRNAs) communicate from cell to cell and travel long distances through the vasculature. However, siRNA movement into germ cells has remained controversial, and has gained interest because the terminally differentiated pollen vegetative nurse cell surrounding the sperm cells undergoes a programmed heterochromatin decondensation and transcriptional reactivation of transposable elements (TEs). Transcription of TEs leads to their post-transcriptional degradation into siRNAs, and it has been proposed that the purpose of this TE reactivation is to generate and load TE siRNAs into the sperm cells. Here, we identify the molecular pathway of TE siRNA production in the pollen grain and demonstrate that siRNAs produced from pollen vegetative cell transcripts can silence TE reporters in the sperm cells. Our data demonstrates that TE siRNAs act non-cell-autonomously, inhibiting TE activity in the germ cells and potentially the next generation.