Mouse X Inactivation

表观遗传修饰调节正常发育和正常发育中的基因表达 疾病，如癌症。X染色体调节是坐标的一个例子 在整个染色体水平上对基因表达的表观遗传调节。我们的目标 是研究哺乳动物中X连锁基因的表观遗传调控。X上的基因 染色体的剂量由两个过程补偿：活性X的上调 两性的染色体，女性的X失活。一个基因子集逃脱了X 失活，因此在雌性中有更高的表达。这些基因的重要性 在正常发育过程中，包括胚胎在内的表型异常 与单个X染色体相关的特纳综合征的致命性。 我们将研究允许逃脱X基因的分子机制 失活在沉默染色质的背景下表达。在目标1中，我们将 建立小鼠和小鼠所有逃脱X失活基因的综合清单 确定它们的染色质结构。我们将使用RNA测序来区分 X连锁基因的每个等位基因在具有两条X染色体的细胞中的表达 从不同的老鼠物种中分离出来，以便根据 物种间的多态现象。我们将绘制染色质的分布图 在活跃或不活跃的X染色体上唯一存在的修饰使用 染色质免疫沉淀(CHIP)结合阵列和测序分析。 基于这些数据，我们将研究特定酶的作用，这些酶建立或 移除与X失活或逃逸相关的特定组蛋白修饰 当X失活时，雌性ES细胞分化。 我们之前的研究表明，逃逸基因的两侧是与 染色质绝缘体元件CTCF，可保护它们免受邻近物质的伤害 异染色质。在目标2中，我们将确定该元素在 构建小鼠X染色体染色质结构的研究 逃逸基因(Jarid1c)两侧CTCF结合位点的突变。的影响 这些突变将在雌性ES细胞和小鼠身上进行检测，以确定 Jarid1c的表达和表观遗传学特征在没有CTCF的情况下发生了变化 有约束力的。 这项研究将促进人们对染色质结构在控制卵巢癌中的作用的理解。 正常生物学和疾病中的基因表达。

Epigenetic modifications modulate gene expression in normal development and in diseases, such as cancer. X chromosome regulation is an example of coordinate epigenetic regulation of gene expression at the level of an entire chromosome. Our goal is to investigate the epigenetic regulation of X-linked genes in mammals. Genes on the X chromosome are dosage compensated by two processes: upregulation of the active X chromosome in both sexes, and X inactivation in females. A subset of genes escapes X inactivation and thus has higher expression in females. The importance of these genes in normal development is illustrated by the phenotypic anomalies including embryonic lethality in Turner syndrome, which is associated with a single X chromosome. We will investigate the molecular mechanisms that allow genes that escape X inactivation to be expressed within the context of silenced chromatin. In Aim 1 we will establish a comprehensive list of all genes that escape X inactivation in mouse and determine their chromatin structure. We will use RNAsequencing to distinguish expression from each allele of X-linked genes in cells with two X chromosomes, each from a different mouse species, so that alleles can be distinguished based on polymorphisms between the species. We will map the distribution of chromatin modifications uniquely present on either the active or inactive X chromosomes using chromatin immunoprecipitation (ChIP) together with array and sequencing analyses. Based on these data we will investigate the role of specific enzymes that establish or remove specific histone modifications in relation to X inactivation or escape during female ES cell differentiation when X inactivation takes place. Our previous studies show that escape genes are flanked by binding sites for the chromatin insulator element CTCF that may protect them from adjacent heterochromatin. In Aim 2 we will determine the functional role of this element in regulating the chromatin structure of the X chromosome by constructing a mouse with mutations at CTCF binding sites that flank an escape gene (Jarid1c). The effects of these mutations will be examined in female ES cells and in mice to determine whether the expression and epigenetic features of Jarid1c are altered in the absence of CTCF binding. This study will advance understanding of the role of chromatin structure in the control of gene expression in normal biology and diseases.