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Imprinting with insulation

William Wells

Author Affiliations

Genome Biology 2000, 1:spotlight-20000531-02  doi:10.1186/gb-spotlight-20000531-02

The electronic version of this article is the complete one and can be found online at:


Published:31 May 2000

© 2000 BioMed Central Ltd

Research news

On the chromosome inherited from the mother, the mammalian H19 gene is active even as the upstream Igf2 gene is silenced. The reverse pattern of expression occurs on the paternal chromosome. Paternal H19 expression is silenced by promoter methylation, whereas paternal Igf2 expression relies on an enhancer located downstream of H19. In the 25 May Nature Bell and Felsenfeld, and Hark et al., find that, on the maternal chromosome, the enhancer's access to the Igf2 promoter is blocked by an intervening insulator (Nature 2000, 405:482-485; 486-489). This block is effected by the binding of the zinc-finger protein CTCF to the hypomethylated maternal insulator. The paternal insulator, however, is methylated and therefore does not bind CTCF or block interactions between the enhancer and the Igf2 promoter.

References

  1. Deletion of the H19 differentially methylated domain results in loss of imprinted expression of H19 and Igf2.

    PubMed Abstract | Publisher Full Text OpenURL

  2. [http://www.nature.com/nature/] webcite

    Nature magazine hompeage