Temporal Patterning of Neural Progenitors to Generate Neural Diversity

神经祖细胞的时间模式产生神经多样性

• 批准号: 10522528
• 负责人: Xin Li
• 金额: $ 37.4万
• 依托单位: UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-01 至 2027-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10522528
• 关键词: ATAC-seq; Age; Binding; Binding Sites; Biological Assay; Birth Order; Cell Cycle; Chromatin; Complex; Cortical Cord; Data; Development; Drosophila genus; Enhancers; Epigenetic Process; Fibrinogen; Generations; Genes; Genetic Transcription; Growth; Health; Human; Invertebrates; Metabolism; Mission; Molecular; Mutate; Nuclear; Organism; Pathway interactions; Pattern; Phenotype; Play; Process; Regulation; Reporter; Research; Retina; Role; Series; Shapes; Signal Transduction; Specific qualifier value; Speed; Spinal Cord; Testing; To specify; Transcriptional Regulation; United States National Institutes of Health; Vertebrates; base; brain abnormalities; chromatin remodeling; developmental disease; experimental study; gene regulatory network; genetic analysis; insight; mutant; nano; nerve stem cell; neural patterning; neuroblast; notch protein; novel; progenitor; recruit; relating to nervous system; single-cell RNA sequencing; transcription factor; transcription regulatory network

Vertebrate and invertebrate neural progenitors are temporally patterned to generate a great diversity of neural types in a birth-order dependent manner. Series of temporal transcription factors (TTF) were found to be sequentially expressed in Drosophila neuroblasts, and they are proposed to form transcriptional cascades to control the sequential generation of different neural types. However, whether the cross-regulations inferred from mutant phenotypes are direct transcriptional regulations haven't been demonstrated. Furthermore, the cross-regulations among TTFs are often not sufficient for the temporal transitions, suggesting other mechanisms are at play to regulate the temporal progression. We use the Drosophila medulla neuroblasts to study these questions. In the previous R01 period, we identified molecular mechanisms controlling transitions to the Slp and Ey temporal stages, and also identified a comprehensive list of novel temporal transcription factors through single-cell RNA sequencing. In this renewal application, we present our preliminary data of single-nuclear ATAC seq, which revealed the dynamic chromatin accessibility during temporal patterning of medulla neuroblasts. Through analyzing the differentially accessible regions, we identified the possible enhancers controlling the temporal expression patterns of TTF genes. Through integration of scRNA-seq and snATACseq and a combination of reporter assays, genetic analysis and Dam-ID experiments, we propose to elucidate the transcriptional regulatory networks controlling the sequential temporal transitions in great detail. Furthermore, we found that different epigenetic factors are required at different steps of temporal patterning. We propose to further examine how they regulate the dynamic chromatin accessibility and how they are recruited to specific target genes during temporal patterning. Finally, we propose to examine the fundamental molecular mechanisms that coordinate the growth/proliferation with TTF cascade progression, and will test our hypothesis that early TTFs have different roles in controlling growth/proliferation than late TTFs through a combination of approaches.

脊椎动物和无脊椎动物的神经祖细胞在时间上形成模式， 神经类型的多样性以出生顺序依赖的方式。时间转录序列 在果蝇成神经细胞中发现TTF因子顺序表达， 提出形成转录级联来控制不同神经元的顺序产生， 类型然而，从突变表型推断的交叉调节是否是直接的， 转录调控尚未得到证实。此外，交叉监管 在TTF之间的时间转换往往是不够的，这表明其他机制 在调节时间进程我们用果蝇髓质成神经细胞 研究这些问题。在前一个R01阶段，我们确定了分子机制 控制过渡到Slp和Ey时间阶段，并确定了一个全面的 通过单细胞RNA测序获得的新型时间转录因子列表。在这次更新中， 应用中，我们提出了我们的单核ATAC序列的初步数据，其中揭示了 动态染色质可及性在延髓成神经细胞的时间模式。通过 通过分析差异可及区域，我们确定了可能的增强子， TTF基因的时间表达模式。通过整合scRNA-seq和 snATACseq和报告基因测定、遗传分析和Dam-ID实验的组合， 我们建议阐明转录调控网络控制的顺序 时间转换的细节。此外，我们发现不同的表观遗传因素是 在时间图案化的不同步骤中需要。我们建议进一步研究他们如何 调节动态染色质可及性以及它们如何被募集到特定的靶基因 在时间模式中。最后，我们建议检查基本的分子 协调生长/增殖与TTF级联进展的机制，并将测试 我们的假设是，早期TTF在控制生长/增殖方面的作用与晚期TTF不同， 专题信托基金通过各种办法相结合。