Transfer RNA Dynamics During Neural Differentiation

神经分化过程中的转移RNA动力学 转移RNAs(TRNAs)远不是不变的信使核糖核酸(Mrna)解码者，而是在基因塑造中起着动态作用。 表情。例如，tRNA的丰度预计会影响mRNA的稳定性：转录产物富含在 最佳密码子(由丰富的tRNAs解码)是稳定的，而转录产物富含非最佳密码子 (由罕见的tRNA解码)是不稳定的。我们将使用果蝇神经干细胞的分化来测试这一模型 细胞(神经母细胞)是与人类神经发育和神经学相关的高度易处理的系统 疾病。我们假设神经母细胞和它们的神经元后代的tRNA水平不同，因此 影响信使核糖核酸的稳定性和微调基因表达，以满足每种细胞类型的需要。我们也 假设神经分化过程中tRNA基因(TDNA)转录受两个非排他性 机制：一种神经特异性抑制物广泛抑制RNA聚合酶III(RPOL3)等 RPOL3的靶向抑制是由于重叠的RNA聚合酶II(RPOL2)依赖的转录。我们 将通过量化tRNA丰度、tRNA转录和mRNA衰变来验证这些假说 神经母细胞和神经元，结合对预测的调控因子的药理学和遗传操作 TDNA转录。我们将使用靶向技术来确定tRNA差异表达的功能意义 TRNA在mRNA衰退、神经发育和行为检测中的下调和过度表达。这部作品 将通过开发改变tRNA表达的新工具来实现，包括 基于CRISPR/CAS9的方法。TRNA表达缺陷与几种神经发育和 神经系统疾病，包括神经退行性疾病、多种形式的小头畸形和脑 癌症。我们将利用我们在果蝇神经生物学和RNA生物学方面的专业知识，显著推动 了解调节正常发育的tRNA表达动态，并在缺陷时起作用 为了疾病。

Transfer RNA Dynamics During Neural Differentiation Far from serving as invariant mRNA decoders, transfer RNAs (tRNAs) play a dynamic role in shaping gene expression. For example, tRNA abundance is expected to affect mRNA stability: transcripts enriched in optimal codons (decoded by abundant tRNAs) are stable while transcripts enriched in non-optimal codons (decoded by rare tRNAs) are unstable. We will test this model using differentiation of Drosophila neural stem cells (neuroblasts) as a highly tractable system with relevance to human neurodevelopment and neurological disease. We hypothesize that tRNA levels differ between neuroblasts and their neuronal progeny, thereby influencing mRNA stability and fine-tuning gene expression to meet the needs of each cell type. We also hypothesize that tRNA gene (tDNA) transcription during neural differentiation is regulated by two non-exclusive mechanisms: widespread repression of RNA polymerase III (RPOL3) by a neural-specific inhibitor and more targeted repression of RPOL3 due to overlapping RNA polymerase II (RPOL2)-dependent transcription. We will test these hypotheses using quantification of tRNA abundance, tRNA transcription and mRNA decay in neuroblasts and neurons, combined with pharmacologic and genetic manipulation of predicted regulators of tDNA transcription. We will determine the functional significance of differential tRNA expression using targeted tRNA knockdown and overexpression in assays of mRNA decay, neurodevelopment and behavior. This work will be made possible through the development of novel tools for altering tRNA expression, including a CRISPR / Cas9-based approach. Defective tRNA expression is implicated in several neurodevelopmental and neurological diseases, including neurodegenerative diseases, multiple forms of microcephaly, and brain cancers. We will use our expertise in Drosophila neurobiology and RNA biology to significantly advance the understanding of tRNA expression dynamics that regulate normal development and, when defective, contribute to disease.