Regulation of proliferation and differentiation in the male germ line adult stem cell lineage

雄性生殖系成体干细胞谱系增殖和分化的调节

• 批准号: 10160936
• 负责人: MARGARET T FULLER
• 金额: $ 85.15万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-06-01 至 2025-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10160936
• 关键词: 3' Untranslated Regions; Alternative Splicing; Architecture; Biological; CSPG6 gene; Cell Communication; Cell Cycle; Cell Lineage; Cells; Chromatin; Communication; Cyclin B; Development; Drosophila genus; Ensure; Failure; G2 Phase; Gene Expression; Genes; Genetic Transcription; Germ Lines; Homologous Gene; Immunoprecipitation; Laboratories; M cell; Maintenance; Malignant Neoplasms; Maps; Meiosis; Messenger RNA; Mitosis; Mitotic; Modeling; Molecular; Process; Production; Proliferating; Prophase; Protein Isoforms; Proteins; RNA-Binding Proteins; Regulation; Site; Spermatocytes; Spermatogonia; Structure; Supporting Cell; System; Tissues; Transcript; Translations; adult stem cell; cell type; in vivo; male; novel; precursor cell; prevent; programs; promoter; recruit; repaired; self-renewal; transcriptome sequencing

Project Summary / Abstract The switch from proliferation to differentiation is a key regulatory point in the adult stem cell lineages that underlie tissue maintenance and repair, and failure to cleanly switch may contribute to genesis of cancer. My laboratory has long used the Drosophila male germ line as a model to investigate how self-renewal, proliferation and differentiation are regulated in adult stem cell lineages. Several lines of our inquiry have recently converged on the molecular mechanisms underlying the developmentally programmed transition from mitotic proliferation to onset of meiosis and differentiation, implicating a number of molecular and cellular mechanisms in regulating this critical switch. We find that RNA binding proteins involved in translational control and alternative splicing act cell autonomously to regulate the cessation of proliferation and that progression of differentiation requires communication from associated somatic support cells. We discovered that a developmentally regulated alternate choice of site at which certain nascent transcripts are cut to form 3' ends, leading to production of novel mRNA isoforms with shortened 3'UTRs, controls dramatic changes in the suite of proteins expressed in differentiating spermatocytes compared to proliferating spermatogonia. We found that dramatic changes in chromatin open over 2000 new promoters with novel core sequence structure to turn on the new cell type specific transcription program when cells initiate spermatocyte differentiation. Some of the earliest genes turned on in this differentiation program encode chromatin associated proteins that prevent spurious opening of normally cryptic promoters, thus preventing massive misexpression of genes associated with the wrong cell type. Other transcripts upregulated with differentiation onset encode cell type-specific translational regulators that delay production of core G2/M cell cycle machinery to program the extended G2 phase of meiotic prophase. Over the next 5 years, we propose to map how these processes collaborate to form the regulatory circuitry that initiates then executes the switch from proliferation to differentiation. We will investigate how the RNA binding proteins Bam and Bgcn trigger the switch from mitosis to meiosis by repressing expression of the alternative splice factor HOW, identify candidate substrates of HOW by immunoprecipitation followed by RNA-Seq, and assess their function in vivo, including whether they communicate with adjacent somatic support cells. We will investigate how the switch in proteins expressed due to alternative 3' end cut site selection on nascent transcripts is regulated and influences differentiation. We will investigate how the differentiation program is kept off in precursor cells and how cell-type specific chromatin regulators and proteins that recruit them to target loci set up the new transcription program for differentiation. To elucidate how the developmental program remodels the cell cycle, we will investigate how cell-type specific RNA binding proteins first repress, then activate translation of cyclin B during meiotic prophase and how the DAZ homolog Boule regulates progression into the meiotic divisions. .

项目摘要 /摘要 从增殖到分化的转换是成年干细胞谱系中的关键调节点 基础组织维护和修复以及无法清洁切换可能有助于癌症的起源。我的 实验室长期以来一直使用果蝇雄性生殖系来研究自我更新的方式 在成年干细胞谱系中调节增殖和分化。我们的询问的几行 最近在从 有丝分裂增殖到减数分裂和分化的发作，暗示了许多分子和细胞 调节此关键开关的机制。我们发现参与转化控制的RNA结合蛋白 和替代剪接ACT ACT细胞自主自主调节的停止和这种进展 分化需要与相关的躯体支持细胞进行通信。我们发现一个 在开发监管的替代选择的位置选择，其中某些新生的转录本被切割为3'端， 导致产生新的mRNA同工型，缩短了3'UTR，控制套件的急剧变化 与增生的精子相比，在分化的精子细胞中表达的蛋白质的蛋白质。我们发现 具有新的核心序列结构的2000新启动子的染色质的急剧变化以开启 当细胞启动精子细胞分化时，新的细胞类型转录程序。一些 该分化程序中最早的基因编码染色质蛋白，以防止 正常隐性启动子的虚假开放，从而防止了相关基因的大规模损害 具有错误的单元格类型。其他成绩单上调，分化构成特定于细胞类型特定于细胞类型 延迟核心G2/M细胞周期机械生产到扩展G2的翻译调节器 减数分裂预言的阶段。在接下来的5年中，我们建议将这些过程合作映射到 形成启动的监管电路，然后执行从增殖到差异的开关。我们将 研究RNA结合蛋白BAM和BGCN如何触发从有丝分裂到减数分裂的开关 抑制替代剪接因素的表达方式，确定如何确定如何通过 免疫沉淀，然后是RNA-Seq，并评估其在体内的功能，包括它们是否是否 与相邻的体细胞交流。我们将研究蛋白质中的开关如何表达 由于替代性3'端切位点的选择，因此在新生转录本上选择并影响分化。 我们将研究如何在前体细胞中保持分化程序以及细胞类型的特定方式。 染色质调节剂和蛋白质招募它们以靶向基因座设置新的转录程序 分化。为了阐明开发程序如何重塑细胞周期，我们将研究 细胞型特异性RNA结合蛋白首先抑制，然后在减数分裂过程中激活细胞周期蛋白B的翻译 预言以及Daz同源性Boule如何调节进展为减数分裂分裂。 。