FUNCTIONAL ANALYSIS OF DIFFERENTLY METHYLATED H19 GENE

这项建议的目的是研究基因组的调控。 母系表达的H19基因在小鼠体内的印迹研究 实验系统。基因组印记是基因的差异表达 等位基因取决于亲本来源。它存在于哺乳动物中，作为一种 因此，某些基因的母本和父本都是 正常发育所必需的。此外，印记还牵涉到 几种人类疾病，对印记的理解可能有助于 对这些人类疾病的纠正。尽管有几个基因已经被 在老鼠和人类身上都有印记，其机制是 父母的身份分配尚不清楚。然而，一位强有力的候选人 等位基因的区别标志是胞嘧啶残基的甲基化。 CpG二核苷酸。对于H19，父亲特有的甲基化序列具有 被鉴定为H19转录所不需要的基因。这个 这项建议的具体目的是确定家长的角色 通过从内源基因座移除序列使H19序列甲基化 利用同源重组，然后通过在小鼠身上研究结果 分析亲本特异的等位基因H19的表达 举止。

The objective of this proposal is to study the regulation of genomic imprinting in mouse using the maternally expressed H19 gene as the experimental system. Genomic imprinting is the differential expression of alleles dependent upon the parental origin. It occurs in mammals and, as a consequence, both a maternal and a paternal copy of certain genes are required for normal development. In addition, imprinting is implicated in several human diseases, and the understanding of imprinting may facilitate the correction of these human diseases. Although several genes have been shown to be imprinted in both mice and humans, the mechanism by which parental identity is assigned is unclear. However, a strong candidate for the differential marking of alleles is methylation of cytosine residues in CpG dinucleotides. For H19, a paternal specific methylated sequence has been identified which is not required for transcription of H19. The specific aim of this proposal is to determine the role of the paternally methylated H19 sequence by removing the sequence from the endogenous locus using homologous recombination and then studying the outcome in mice by analyzing H19 expression from the disrnpted allele in a parental-specific manner.