Deletion of the H19 differentially methylated domain results in loss of imprinted expression of H19 and Igf2
Deletion of the H19 differentially methylated domain results in loss of imprinted expression of H19 and Igf2
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DOI：
10.1101/gad.12.23.3693
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发表时间：
1998-12-01
影响因子：
10.5
通讯作者：
Bartolomei, MS
中科院分区：
文献类型：
--
作者：
Thorvaldsen, JL;Duran, KL;Bartolomei, MS
与印迹基因相关的差异甲基化序列被提出用于控制基因组印迹。在整个发育过程中，位于印迹小鼠H19基因5'处的2kb区域在非活性父本等位基因上高度甲基化。为了确定内源性位点上的印迹表达是否需要这种差异甲基化结构域（DMD），我们培养了具有1.6 kb DMD靶向缺失的小鼠，并检测了H19和相关的反向印迹Igf2基因的等位基因表达。当DMD缺失是父系遗传时，H19被激活，Igf2表达降低；相反，在母体传播突变后，H19表达降低，Igf2被激活。与DMD建立甲基化印记的假设作用一致，该突变也扰乱了剩余H19序列的等位基因特异性甲基化。总之，这些实验表明H19高甲基化的5'侧链序列是沉默父系衍生的H19所必需的。此外，这些实验证明了DMD在母体染色体上的新作用，它是H19的最大表达和Igf2沉默所必需的。因此，H19差异甲基化序列对于H19和Igf2印迹都是必需的。
Differentially methylated sequences associated with imprinted genes are proposed to control genomic imprinting. A 2-kb region located 5' to the imprinted mouse H19 gene is hypermethylated on the inactive paternal allele throughout development. To determine whether this differentially methylated domain (DMD) is required for imprinted expression at the endogenous locus, we have generated mice harboring a 1.6-kb targeted deletion of the DMD and assayed for allelic expression of H19 and the linked, oppositely imprinted Igf2 gene. H19 is activated and Igf2 expression is reduced when the DMD deletion is paternally inherited; conversely, upon maternal transmission of the mutation, H19 expression is reduced and Igf2 is activated. Consistent with the DMD's hypothesized role of setting up the methylation imprint, the mutation also perturbs allele-specific methylation of the remaining H19 sequences. In conclusion, these experiments show that the H19 hypermethylated 5' flanking sequences are required to silence paternally derived H19. Additionally, these experiments demonstrate a novel role for the DMD on the maternal chromosome where it is required for the maximal expression of H19 and the silencing of Igf2. Thus, the H19 differentially methylated sequences are required for both H19 and Igf2 imprinting.