Imprinting studies of a paternally expressed Usp29 gene

描述（由申请人提供）：由于驻留基因的异常功能半合子性，印迹区域与几种不同类型的人类遗传缺陷有关，从神经缺陷到癌症。我们已经在人类染色体19q13.4 （HSA19q13.4）上发现了一个印迹结构域，这个区间也与人类和小鼠的印迹相关遗传疾病有关。该结构域包含至少6个印迹基因，包括Peg3、Usp29、Zim3/Usp29-as、Zim1、Zim2和Zfp264。与其他印迹结构域一样，基因聚类被认为反映了远程控制机制的存在。这项工作的长期目标是了解该区域内每个基因的印迹表达是如何被调节的；该项目特别关注两个父系表达的保守基因Peg3和Usp29的调控。比较基因组研究使我们能够确定一个差异甲基化区域，我们认为该区域可能作为该区间的印迹控制区（ICR）。这种潜在的ICR与Peg3和Usp29的启动子区域重叠，称为P1-DMR（启动子1-差异甲基化区域）。我们还发现了一个进化上保守的gli型锌指基因YY1作为P1-DMR的甲基化敏感反式因子。我们预测P1-DMR/YY1可能作为甲基化敏感染色体绝缘子或神经增强子控制邻近基因的印迹。为了研究P1-DMR在印迹控制方面的潜在功能，我们将使用几种基于细胞系的检测系统分析P1-DMR观察到的绝缘子和启动子活性。将产生携带P1-DMR靶向缺失的突变小鼠，以测试P1-DMR的体内功能，并使用遗传各种报告基因构建的转基因小鼠来研究YY1在P1-DMR功能中的潜在作用。这些结果将为该印迹区域的调控提供新的见解，并探索YY1作为一个反式因子在哺乳动物基因组印迹中的可能作用。这些研究将为人类和小鼠与该结构域相关的印迹相关表型提供新的线索。

DESCRIPTION (provided by applicant): Due to the unusual functional hemizygosity of the resident genes, imprinted regions have been linked to several different kinds of human genetic defects, ranging from neurological defects to cancer. We have characterized one imprinted domain located in human chromosome 19q13.4 (HSA19q13.4), and this interval is also associated with imprinting related genetic disorders in human and mouse. This domain contains at least 6 imprinted genes, including Peg3, Usp29, Zim3/Usp29-as, Zim1, Zim2, and Zfp264. As in other imprinted domains gene clustering is thought to reflect the presence of long-range controlling mechanism(s). The long-term goal of this work is to understand how the imprinted expression of each gene within this domain is regulated; the proposed project is focused specifically on the regulation of two paternally expressed conserved genes, Peg3 and Usp29. Comparative genomic studies allowed us to identify one differentially methylated region that we believe may serve as an Imprinting Control Region (ICR) for this interval. This potential ICR overlaps with the promoter region of Peg3 and Usp29, termed P1-DMR (Promoter 1-Differentially Methylated Region). We have also identified an evolutionarily conserved Gli-type zinc-finger gene YY1 as a methylation-sensitive trans factor for P1-DMR. We predict that P1-DMR/YY1 may function either as a methylation sensitive chromosomal insulator or neural enhancer for the imprinting control of the neighboring genes. To investigate the potential function of P1-DMR for imprinting control, we will analyze the insulator and promoter activity observed from P1-DMR using several cell-line based assay systems. Mutant mice carrying targeted deletions of P1-DMR will be generated to test the in vivo function of P1-DMR, and the potential roles of YY1 in the P1-DMR function will also be investigated using transgenic mice inheriting various reporter constructs. These results will provide new insights into the regulation of this imprinted region, and explore the possible role of YY1 as a trans factor for mammalian genomic imprinting. These studies will provide new clues to imprinting-related phenotypes linked to this domain in human and mouse.