PDF(Pubmed)
Abstract：
The Maternal-to-Zygotic transition (MZT) is a reprograming process encompassing zygotic genome activation (ZGA) and the clearance of maternally-provided mRNAs. While some factors regulating MZT have been identified, there are thousands of maternal RNAs whose function has not been ascribed yet. Here, we have performed a proof-of-principle CRISPR-RfxCas13d maternal screening targeting mRNAs encoding protein kinases and phosphatases in zebrafish and identified Bckdk as a novel post-translational regulator of MZT. Bckdk mRNA knockdown caused epiboly defects, ZGA deregulation, H3K27ac reduction and a partial impairment of miR-430 processing. Phospho-proteomic analysis revealed that Phf10/Baf45a, a chromatin remodeling factor, is less phosphorylated upon Bckdk depletion. Further, phf10 mRNA knockdown also altered ZGA and Phf10 constitutively phosphorylated rescued the developmental defects observed after bckdk mRNA depletion. Altogether, our results demonstrate the competence of CRISPR-RfxCas13d screenings to uncover new regulators of early vertebrate development and shed light on the post-translational control of MZT mediated by protein phosphorylation.
摘要：
母体到合子的转变（MZT）是一个重编程过程，包括合子基因组激活（ZGA）和母体提供的mRNA的清除。虽然已经确定了一些调节MZT的因素，有成千上万的母体RNA的功能尚未被归因于。这里,我们在斑马鱼中针对编码蛋白激酶和磷酸酶的mRNA进行了CRISPR-RfxCas13d母体筛选,并确定Bckdk是一种新型的MZT翻译后调节因子.BckdkmRNA敲低导致外突缺损，ZGA放松管制，H3K27ac减少和miR-430加工的部分损害。磷酸蛋白质组分析显示，Phf10/Baf45a，染色质重塑因子，在Bckdk耗尽时磷酸化较少。Further,phf10mRNA敲低也改变了ZGA，而Phf10组成型磷酸化挽救了bckdkmRNA耗竭后观察到的发育缺陷。总之,我们的结果证明了CRISPR-RfxCas13d筛选能够发现早期脊椎动物发育的新调节因子,并阐明了蛋白质磷酸化介导的MZT翻译后控制.
