A 5' 2-kilobase-pair region of the imprinted mouse H19 gene exhibits exclusive paternal methylation throughout development.
The imprinted mouse H19 gene is hypermethylated on the inactive paternal allele in somatic tissues and sperm. Previous observations from a limited analysis have suggested that methylation of a few CpG dinucleotides in the region upstream from the start of transcription may be the mark that confers parental identity to the H19 alleles. Here we exploit bisulfite mutagenesis coupled with genomic sequencing to derive the methylation status of 68 CpGs that reside in a 4-kb region 5' to the start of transcription. This method reveals a 2-kb region positioned between 2 and 4 kb upstream from the start of transcription that is strikingly differentially methylated in midgestation embryos. At least 12 of the cytosine residues in this region are exclusively methylated on the paternal allele in blastocysts. In contrast, a 350-bp promoter-proximal region is less differentially methylated in midgestation embryos and, like most of the genome, is largely devoid of methylation on both alleles in blastocysts. We also demonstrate exclusive expression of the maternal H19 allele in the embryos that exhibit paternal methylation of the upstream 2-kb region. These data suggest that the 2-kb differentially methylated region acts as a key regulatory domain for imprinted H19 expression.
Tremblay
K D
KD
Howard Hughes Medical Institute and Department of Cell and Developmental Biology, University of Pennsylvania School of Medicine, Philadelphia 19104, USA.
Duran
K L
KL
Bartolomei
M S
MS
D000483:Alleles; D000818:Animals; D001755:Blastocyst; D003596:Cytosine / Q000378:metabolism; D019175:DNA Methylation; D005314:Embryonic and Fetal Development / Q000235:genetics; D005796:Genes; D018392:Genomic Imprinting / Q000235:genetics*; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D009124:Muscle Proteins / Q000235:genetics*; D016296:Mutagenesis; D011401:Promoter Regions, Genetic; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated; D013447:Sulfites; D014158:Transcription, Genetic / Q000235:genetics
C094335:H19 long non-coding RNA; D009124:Muscle Proteins; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated; D013447:Sulfites; D003596:Cytosine; C009279:sodium bisulfite