Tens of thousands of rapidly evolving long non-coding RNA (lncRNA) genes have been identified, but functions were assigned to relatively few of them. The lncRNA contribution to the mouse oocyte physiology remains unknown. We report the evolutionary history and functional analysis of Sirena1, the most expressed lncRNA and the 10th most abundant poly(A) transcript in mouse oocytes. Sirena1 appeared in the common ancestor of mouse and rat and became engaged in two different post-transcriptional regulations. First, antisense oriented Elob pseudogene insertion into Sirena1 exon 1 is a source of small RNAs targeting Elob mRNA via RNA interference. Second, Sirena1 evolved functional cytoplasmic polyadenylation elements, an unexpected feature borrowed from translation control of specific maternal mRNAs. Sirena1 knock-out does not affect fertility, but causes minor dysregulation of the maternal transcriptome. This includes increased levels of Elob and mitochondrial mRNAs. Mitochondria in Sirena1-/- oocytes disperse from the perinuclear compartment, but do not change in number or ultrastructure. Taken together, Sirena1 contributes to RNA interference and mitochondrial aggregation in mouse oocytes. Sirena1 exemplifies how lncRNAs stochastically engage or even repurpose molecular mechanisms during evolution. Simultaneously, Sirena1 expression levels and unique functional features contrast with the lack of functional importance assessed under laboratory conditions.

中文翻译：

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最丰富的产妇lncRNA Sirena1在转录后起作用并影响线粒体分布。

已经鉴定了成千上万个迅速发展的长非编码RNA（lncRNA）基因，但功能却很少。lncRNA对小鼠卵母细胞生理的贡献仍然未知。我们报告Sirena1，小鼠卵母细胞中表达最多的lncRNA和第十个最丰富的poly（A）成绩单的进化历史和功能分析。Sirena1出现在小鼠和大鼠的共同祖先中，并参与了两种不同的转录后调控。首先，将反义的Elob假基因插入Sirena1外显子1是通过RNA干扰靶向Elob mRNA的小RNA的来源。其次，Sirena1进化了功能性胞质聚腺苷酸化元件，这是特定母体mRNA的翻译控制所借用的意外功能。Sirena1基因敲除不影响生育力，但会导致母亲转录组的轻微失调。这包括Elob和线粒体mRNA的水平增加。Sirena1-/-卵母细胞中的线粒体从核周区散开，但数量或超微结构没有变化。总之，Sirena1有助于小鼠卵母细胞中的RNA干扰和线粒体聚集。Sirena1举例说明了lncRNA在进化过程中如何随机地参与甚至改变分子机制。同时，Sirena1表达水平和独特的功能特征与在实验室条件下评估的功能重要性不足形成鲜明对比。但不要改变数量或超微结构。总之，Sirena1有助于小鼠卵母细胞中的RNA干扰和线粒体聚集。Sirena1举例说明了lncRNA在进化过程中如何随机地参与甚至改变分子机制。同时，Sirena1表达水平和独特的功能特征与在实验室条件下评估的功能重要性不足形成鲜明对比。但不要改变数量或超微结构。总之，Sirena1有助于小鼠卵母细胞中的RNA干扰和线粒体聚集。Sirena1举例说明了lncRNA在进化过程中如何随机地参与甚至改变分子机制。同时，Sirena1表达水平和独特的功能特征与在实验室条件下评估的功能重要性不足形成鲜明对比。