Translatome analysis at the egg-to-embryo transition in sea urchin
Translatome analysis at the egg-to-embryo transition in sea urchin
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DOI：
10.1093/nar/gky258
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发表时间：
2018-05-18
影响因子：
14.9
通讯作者：
Morales, Julia
中科院分区：
文献类型：
--
作者：
Chasse, Heloise;Aubert, Julie;Morales, Julia
早期胚胎发生依赖于母体储存的 mRNA 的翻译调控。在海胆中，受精会引发翻译活动的急剧增加，这是细胞分裂开始所必需的。在这里，通过多核糖体分析和测序研究了受精时翻译的 mRNA 的全谱。早期海胆胚胎的翻译组提供了受精后多核糖体招募动态的完整图像。我们的结果表明，只有一部分母体 mRNA 被选择性地招募到多核糖体上，在翻译集中具有过度代表性的功能类别。受精时翻译的增加取决于 mTOR 途径激活后翻译起始复合物的形成。令人惊讶的是，mTOR 通路抑制对新翻译的 mRNA 的多核糖体募集有不同的影响，因此看起来要么依赖于 mTOR，要么不依赖于 mTOR。因此，我们的数据主张在早期开发中替代经典的依赖于大写的翻译模型。受精后翻译的 mRNA 的鉴定有助于将翻译激活事件分配给特定的 mRNA。该翻译组是全面分析控制受精翻译的分子机制和控制卵子到胚胎转变以及胚胎发生早期步骤的翻译调控网络的第一步。
Early embryogenesis relies on the translational regulation of maternally stored mRNAs. In sea urchin, fertilization triggers a dramatic rise in translation activity, necessary for the onset of cell division. Here, the full spectrum of the mRNAs translated upon fertilization was investigated by polysome profiling and sequencing. The translatome of the early sea urchin embryo gave a complete picture of the polysomal recruitment dynamics following fertilization. Our results indicate that only a subset of maternal mRNAs were selectively recruited onto polysomes, with over-represented functional categories in the translated set. The increase in translation upon fertilization depends on the formation of translation initiation complexes following mTOR pathway activation. Surprisingly, mTOR pathway inhibition differentially affected polysomal recruitment of the newly translated mRNAs, which thus appeared either mTOR-dependent or mTOR-independent. Therefore, our data argue for an alternative to the classical cap-dependent model of translation in early development. The identification of the mRNAs translated following fertilization helped assign translational activation events to specific mRNAs. This translatome is the first step to a comprehensive analysis of the molecular mechanisms governing translation upon fertilization and the translational regulatory networks that control the egg-to-embryo transition as well as the early steps of embryogenesis.