Functions of PRDM Histone Methyltransferases in Cranial Neural Crest Cell Development

项目摘要/摘要 PRDM(正调控结构域)是一种染色质修饰物，可在表观遗传上调节基因转录 通过它们的组蛋白甲基转移酶活性或通过与其他蛋白质和组蛋白形成络合物- 修饰酶。在需要精确的空间和时间控制基因的过程中，PRDM是至关重要的 表情。头面部骨骼的形成需要各种细胞过程的适当协调。 在脑神经脊细胞(CNCC)的发育中，包括细胞迁移、增殖、分化、极性和 细胞死亡。在CNCC发育过程中发生的任何变化都与先天性 畸形和颅面畸形，如伴有或不伴有腭裂的唇裂。这些先天缺陷非常严重 这很常见，通常以惊人的速度发生(仅在美国每年就有1：1000的活产儿)。因此，它是 有必要了解控制CNCC发展的基因调控网络，以便更好地 了解这些过程的中断如何导致头面部缺陷。已链接多个PRDM 到头面部疾病。人类全基因组关联研究发现了PRDM3和PRDM3的突变 PRDM16与腭裂患者相关。对斑马鱼和小鼠的研究表明，Prdm1、Prdm3 和Prdm16导致软骨骨骼元素发育不良和颅神经节的变化 腭裂。拟议的研究将审查Prdm1a、Prdm3和Prdm16在#年的重要性。 头面部骨骼的形成。在两个重点目标中，这项拟议的研究将定义监管 Prdm1a、Prdm3和Prdm16在CNCC发育中的作用。斑马鱼的初步数据表明 Prdm1a、prdm3和prdm16只会导致轻微的头面部缺陷，很大程度上是由于遗传补偿。 在这三个基因之间。此外，最初的转录图谱研究导致了中心假设 Prdm1a、Prdm3和PRDM16在CNCC发育过程中相互补充，共同发挥双重作用： (1)调节与维持细胞极性有关的基因的表达；(2)控制特定基因的表达 CNCC细胞的命运。在目标1中，CNCC软骨细胞凝聚/极化的机制(S) 并将调查对失去prdm1a、prdm3和prdm16的不同CNCC命运决策的监管。在……里面 目的2，在缺乏prdm3和prdm16的CNCC中，染色质景观的变化将在 可能的Prdm3和Prdm16神经元和细胞极性靶基因以及其他已确定的直接靶基因 通过Prdm~3和Prdm~16芯片序列实验。这项研究将为分子途径提供新的见解。 以及在CNCC发展和形成过程中由Prdm1a、Prdm3和Prdm16调节的靶 头面部骨骼。更好地了解cNCC中的Prdm1a、Prdm3和Prdm16将推动当前的 了解基因表达和细胞通路，如软骨细胞的极性和CNCC的命运 决定，是在颅面发育期间协调的。这些信息在更好的未来将是必不可少的 了解神经脊是如何导致先天性缺陷的。

Project Abstract/Summary PRDMs (Positive Regulatory Domain) are chromatin modifiers that epigenetically regulate gene transcription through their histone methyltransferase activity or by forming complexes with other proteins and histone- modifying enzymes. PRDMs are crucial in processes that need precise spatially and temporally controlled gene expression. The formation of the craniofacial skeleton requires proper orchestration of various cellular processes in cranial neural crest cell (cNCC) development, including cell migration, proliferation, differentiation, polarity and cell death. Any alterations that occur during the process of cNCC development are associated with congenital defects and craniofacial abnormalities such as cleft lip with or without cleft palate. These birth defects are very common, often occurring at alarming rates (1:1000 live births annually in the US alone). Therefore, it is necessary to understand the gene-regulatory networks that control cNCC development in order to better understand how disruption of these processes leads to craniofacial defects. Several PRDMs have been linked to craniofacial disorders. Human genome-wide association studies have identified mutations in PRDM3 and PRDM16 linked to patients with cleft palate. Studies in zebrafish and mice have shown loss of Prdm1, Prdm3 and Prdm16 causes hypoplasia of cartilage skeletal elements and changes in the cranial ganglia in addition to cleft palate. The proposed research will examine the importance of Prdm1a, Prdm3 and Prdm16 during formation of the craniofacial skeleton. In two focused aims, this proposed study will define the regulatory roles of Prdm1a, Prdm3, and Prdm16 in cNCC development. Preliminary data in zebrafish suggests loss of prdm1a, prdm3, and prdm16 causes only mild craniofacial defects, in large part due to genetic compensation between all three genes. In addition, initial transcriptional profiling studies led to the central hypothesis that prdm1a, prdm3, and prdm16 genetically compensate for each other and share dual roles in cNCC development: (1) mediating expression of genes associated with maintaining cell polarity and (2) controlling genes that specify cNCC cell fates. In Aim 1, the mechanism(s) responsible for cNCC chondrocyte cellular condensation/polarity and regulation of different cNCC fate decisions with loss of prdm1a, prdm3, and prdm16 will be investigated. In Aim 2, the changes in the chromatin landscape in prdm3- and prdm16-deficient cNCC will be assessed at putative Prdm3 and Prdm16 neuronal and cell polarity target genes as well as other direct target genes identified by Prdm3 and Prdm16 ChIP-seq experiments. This study will provide new insights into the molecular pathways and targets regulated by Prdm1a, Prdm3 and Prdm16 during cNCC development and the formation of the craniofacial skeleton. A better understanding of Prdm1a, Prdm3, and Prdm16 in cNCCs will advance the current knowledge of how gene expression and cellular pathways, such as chondrocyte cell polarity and cNCC fate decisions, are coordinated during craniofacial development. Such information will be essential in better understanding how neural crest associated congenital defects arise.