Analysis of Pax2 target genes involved in metanephric kidney morphogenesis

人类基因组包含了制造数千种特殊细胞和组织的所有信息 在胚胎发育期间。尽管所有细胞都含有相同的基因， 需要在发育过程中选择性地激活和抑制基因。未能正确调节 这种基因选择性的过程导致癌症、发育异常、细胞变性， 许多其他疾病。细胞分化过程中的基因激活和抑制模式是 由表观遗传机制指定的，可遗传的和可修改的。真核染色质 由DMA包裹在组蛋白八聚体上组成。通过乙酰化修饰核心组蛋白尾部， 磷酸化、甲基化或泛素化可以显著改变局部染色质结构， 基因表达的潜力。积累的生物化学和遗传学证据表明， 组蛋白H3和H4的特异性赖氨酸残基可以决定基因是否保持可接近性。 转录机制或是否沉默成紧密包装的异染色质。如此后生 组蛋白的修饰可以解释胚胎发育过程中可遗传的细胞记忆， 可以极大地影响病变和衰老细胞中的基因表达模式。 Pax 2基因编码一种DNA结合蛋白，对于指定肾脏和泌尿生殖系统是必需的。 在发育早期就有。Pax 2功能丧失导致完全性肾发育不全。然而，过度表达 Pax 2与多种肾脏疾病相关，包括癌症和多囊肾病。 最近，我们发现了一种将Pax 2与哺乳动物组蛋白H3赖氨酸4甲基转移酶连接起来的蛋白质 复杂.为了了解这种复合物如何调节肾脏模式和疾病，我们必须确定 这些基因由Pax 2直接调控，并决定Pax 2/DNA相互作用的位点。这个propsal 将采取系统的方法来确定小鼠体内Pax 2靶基因和Pax 2结合位点 基因组我们将展示这些结合位点的表观遗传印记模式的变化， Pax 2活性。使用胚胎组织和细胞培养模型，我们将测试 Pax 2/DNA的相互作用，并在这些网站的组蛋白甲基化修饰的特点。这些 实验将确定指定细胞命运的发育调节基因如何改变染色质 以可遗传的方式。

The human genome contains all of the information to make thousands of specialized cells and tissues during embryonic development. Even though all cells contain the same genes, cellular differentiation requires the selective activation and suppression of genes during development. Failure to correctly regulate this process of gene selectivity results in cancer, developmental abnormalities, cellular degeneration, and many other disease states. Gene activation and suppression patterns during cellular differentiation are specified by epigenetic mechanisms that are heritable and subject to modifications. Eukaryotic chromatin consists of DMA wrapped around a histone octamer. Modification of the core histone tails by acetylation, phosphorylation, methylation or ubiquitination can dramatically alter the local chromatin structure and the potential for gene expression. Accumulated biochemical and genetic evidence indicates that methylation at specific lysine residues of histones H3 and H4 can determine whether a gene remains accessible to the transcription machinery or whether it is silenced into tightly packaged heterochromatin. Such epigentic modifications of histones could account for a heritable cellular memory during embryonic development and could greatly affect gene expression patterns in diseased and aging cells. The Pax2 gene encodes a DNA binding protein and is essential for specifying the kidney and urogenital tract early in development. Loss of Pax2 function results in complete renal agenesis. Yet, overexpression of Pax2 is associated with a variety or renal diseases, including cancer and polycystic kidney disease. Recently, we identified a protein that links Pax2 to a mammalian histone H3 lysine 4 methyltransferase complex. In order to understand how this complex regulates renal patterning and disease, we must identify genes that are directly regulated by Pax2 and determine the sites of Pax2/DNA interactions. This propsal will take a systematic approach to define Pax2 target genes and Pax2 binding sites within the mouse genome. We will demonstrate changes in epigenetic imprinting patterns at these binding sites in response to Pax2 activity. Using both embryonic tissues and cell culture models, we will test the significance of Pax2/DNA interactions and characterize the modifcations of histone methylation at these sites. These experiments will define how a developmental regulatory gene that specifies cell fate can alter chromatin structure in a heritable way.