This Article Full Text Full Text (PDF) Supplemental Research Data Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Pauler, F. M. Articles by Barlow, D. P. Search for Related Content PubMed PubMed Citation Articles by Pauler, F. M. Articles by Barlow, D. P. Social Bookmarking                   What's this?

Letter

Long-range DNase I hypersensitivity mapping reveals the imprinted Igf2r and Air promoters share cis-regulatory elements

CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Institute of Genetics, Max F. Perutz Laboratories, Vienna Biocenter, A1030 Vienna, Austria

Epigenetic mechanisms restrict the expression of imprinted genes to one parental allele in diploid cells. At the Igf2r/Air imprinted cluster on mouse chromosome 17, paternal-specific expression of the Air noncoding RNA has been shown to silence three genes in cis: Igf2r, Slc22a2, and Slc22a3. By an unbiased mapping of DNase I hypersensitive sites (DHS) in a 192-kb region flanking Igf2r and Air, we identified 21 DHS, of which nine mapped to evolutionarily conserved sequences. Based on the hypothesis that silencing effects of Air would be directed towards cis regulatory elements used to activate genes, DHS are potential key players in the control of imprinted expression. However, in this 192-kb region only the two DHS mapping to the Igf2r and Air promoters show parental specificity. The remaining 19 DHS were present on both parental alleles and, thus, have the potential to activate Igf2r on the maternal allele and Air on the paternal allele. The possibility that the Igf2r and Air promoters share the same cis-acting regulatory elements, albeit on opposite parental chromosomes, was supported by the similar expression profiles of Igf2r and Air in vivo. These results refine our understanding of the onset of imprinted silencing at this cluster and indicate the Air noncoding RNA may specifically target silencing to the Igf2r promoter.

¹ Corresponding author.
E-mail denise.barlow{at}univie.ac.at; fax 43 1 4277 9546.

[Supplemental material is available online at www.genome.org.]

CiteULike    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?