Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 1997 May 1;25(9):1727-35.
doi: 10.1093/nar/25.9.1727.

Chromatin structure and methylation of rat rRNA genes studied by formaldehyde fixation and psoralen cross-linking

Affiliations

Chromatin structure and methylation of rat rRNA genes studied by formaldehyde fixation and psoralen cross-linking

I Stancheva et al. Nucleic Acids Res. .

Abstract

By using formaldehyde cross-linking of histones to DNA and gel retardation assays we show that formaldehyde fixation, similar to previously established psoralen photocross-linking, discriminates between nucleosome- packed (inactive) and nucleosome-free (active) fractions of ribosomal RNA genes. By both cross-linking techniques we were able to purify fragments from agarose gels, corresponding to coding, enhancer and promoter sequences of rRNA genes, which were further investigated with respect to DNA methylation. This approach allows us to analyse independently and in detail methylation patterns of active and inactive rRNA gene copies by the combination of Hpa II and Msp I restriction enzymes. We found CpG methylation mainly present in enhancer and promoter regions of inactive rRNA gene copies. The methylation of one single Hpa II site, located in the promoter region, showed particularly strong correlation with the transcriptional activity.

PubMed Disclaimer

Similar articles

Cited by

References

    1. Biochem Biophys Res Commun. 1973 May 15;52(2):504-10 - PubMed
    1. Mol Cell Biol. 1996 Jan;16(1):414-21 - PubMed
    1. Cell. 1978 Nov;15(3):945-54 - PubMed
    1. Cell. 1981 Nov;26(3 Pt 1):381-90 - PubMed
    1. J Mol Biol. 1981 Oct 15;152(1):1-17 - PubMed