Tissue-specific and imprinted epigenetic modifications of the human NDN gene

JCY Lau, ML Hanel, R Wevrick - Nucleic acids research, 2004 - academic.oup.com
JCY Lau, ML Hanel, R Wevrick
Nucleic acids research, 2004academic.oup.com
Allele-specific DNA methylation, histone acetylation and histone methylation are recognized
as epigenetic characteristics of imprinted genes and imprinting centers (ICs). These
epigenetic modifications are also used to regulate tissue-specific gene expression.
Epigenetic differences between alleles can be significant either in the function of the IC or in
the cis-acting effect of the IC on 'target'genes responding to it. We have now examined the
epigenetic characteristics of NDN, a target gene of the chromosome 15q11–q13 Prader …
Abstract
Allele-specific DNA methylation, histone acetylation and histone methylation are recognized as epigenetic characteristics of imprinted genes and imprinting centers (ICs). These epigenetic modifications are also used to regulate tissue-specific gene expression. Epigenetic differences between alleles can be significant either in the function of the IC or in the cis -acting effect of the IC on ‘target’ genes responding to it. We have now examined the epigenetic characteristics of NDN , a target gene of the chromosome 15q11–q13 Prader–Willi Syndrome IC, using sodium bisulfite sequencing to analyze DNA methylation and chromatin immunoprecipitation to analyze histone modifications. We observed a bias towards maternal allele-specific DNA hypermethylation of the promoter CpG island of NDN , independent of tissue-specific transcriptional activity. We also found that NDN lies in a domain of paternal allele-specific histone hyperacetylation that correlates with transcriptional state, and a domain of differential histone H3 lysine 4 di- and tri-methylation that persists independent of transcription. These results suggest that DNA methylation and histone H3 lysine 4 methylation are persistent markers of imprinted gene regulation while histone acetylation participates in tissue-specific activity and silencing in somatic cells.
Oxford University Press