DNA Damage Signaling and Transcriptome Regulation in Drosophila Embryogenesis

：胚胎发育的忠实执行依赖于有机体适应压力的能力。在果蝇早期胚胎中，核尘埃的过程能够选择性地消除在中期囊胚过渡期间出现复制缺陷或过度DNA损伤的细胞核。长期以来，控制核辐射的分子机制一直知之甚少。在最近的一项研究中，我们的团队定义了一种新的机制，通过这种机制，由Chk2激酶介导的DNA损伤信号导致转录的mRNAs选择性地保留在尘埃核中，阻止编码关键蛋白的转录本的翻译。我们的工作发现茎环结合蛋白(SLBP)是组蛋白mRNA核输出所需的RNA结合蛋白(RBP)，是Chk2的直接靶标。虽然SLBP是解释组蛋白mRNA在尘埃核中保留的关键靶点，但其他几个mRNAs是通过SLBP不依赖的机制保留的。因此，我们

: The faithful execution of embryonic development relies on the capacity of organisms to adapt to stress. In early stage Drosophila embryos, a process of nuclear fallout enables the selective elimination of nuclei with replication defects or excessive DNA damage during the midblastula transition. The molecular mechanisms controlling nuclear fallout have long remained poorly understood. In a recent study, our group defined a novel mechanism through which DNA-damage signalling mediated by the Chk2 kinase leads to the selective retention of transcribed mRNAs in fallout nuclei, blocking the translation of transcripts encoding key proteins. Our work identified the stem loop binding protein (SLBP), an RNA binding protein (RBP) required for histone mRNA nuclear export, as a direct target Chk2. While SLBP is a key target explaining histone mRNA nuclear retention in fallout nuclei, several other mRNAs are retained through SLBP-independent mechanisms. Thus, we