2018年1月15日，Nature genetics发表了题为“Paternal easiRNAs regulate parental genome dosage in Arabidopsis”的文章。

本研究发现，easiRNAs形成父系染色体数量的定量信号，并且他们的平衡剂量是受精后基因组稳定性和种子生存力所需要的。

亲代基因组剂量的调节在动物和植物中是非常重要的，例如X染色体失活和剂量补偿。 “三倍体障碍”是植物中剂量调节的经典实例，其在染色体数目不同的物种之间建立生殖屏障。这种屏障作用于胚胎营养的胚乳组织中，并通过未知的机制诱导杂交种子的夭折。在这里，我们发现在拟南芥中，父本表观激活小干扰RNAs（easiRNAs）的损耗会绕过三倍体障碍响应，增加父系倍性。父本丧失植物特异性RNA聚合酶IV可以抑制easiRNA的形成，并通过恢复在转座元件（TEs）处由小RNA指导的DNA甲基化来挽救三倍体种子，这与由父本表达的印迹基因（PEGs）的表达量减少相关联。我们的数据表明，easiRNAs形成父系染色体数量的定量信号，并且他们的平衡剂量是受精后基因组稳定性和种子生存力所需要的。

The regulation of parental genome dosage is of fundamental importance in animals and plants, as exemplified by X-chromosome inactivation and dosage compensation. The ‘triploid block’ is a classic example of dosage regulation in plants that establishes a reproductive barrier between species differing in chromosome number. This barrier acts in the embryo-nourishing endosperm tissue and induces the abortion of hybrid seeds through a yet unknown mechanism. Here we show that depletion of paternal epigenetically activated small interfering RNAs (easiRNAs) bypasses the triploid block in response to increased paternal ploidy in Arabidopsis thaliana. Paternal loss of the plant-specific RNA polymerase IV suppressed easiRNA formation and rescued triploid seeds by restoring small-RNA-directed DNA methylation at transposable elements (TEs), correlating with reduced expression of paternally expressed imprinted genes (PEGs). Our data suggest that easiRNAs form a quantitative signal for paternal chromosome number and that their balanced dosage is required for post-fertilization genome stability and seed viability.