title: Epigenetic memory at embryonic enhancers identified in DNA methylation maps from adult mouse tissues.
abstract: Mammalian development requires cytosine methylation, a heritable epigenetic mark of cellular memory believed to maintain a cell's unique gene expression pattern. However, it remains unclear how dynamic DNA methylation relates to cell type-specific gene expression and animal development. Here, by mapping base-resolution methylomes in 17 adult mouse tissues at shallow coverage, we identify 302,864 tissue-specific differentially methylated regions (tsDMRs) and estimate that >6.7% of the mouse genome is variably methylated. Supporting a prominent role for DNA methylation in gene regulation, most tsDMRs occur at distal cis-regulatory elements. Unexpectedly, some tsDMRs mark enhancers that are dormant in adult tissues but active in embryonic development. These 'vestigial' enhancers are hypomethylated and lack active histone modifications in adult tissues but nevertheless exhibit activity during embryonic development. Our results provide new insights into the role of DNA methylation at tissue-specific enhancers and suggest that epigenetic memory of embryonic development may be retained in adult tissues.
authors.affiliation: Ludwig Institute for Cancer Research, La Jolla, California, USA.
authors.forename: Gary C
authors.initials: GC
authors.lastname: Hon
authors.forename: Nisha
authors.initials: N
authors.lastname: Rajagopal
authors.forename: Yin
authors.initials: Y
authors.lastname: Shen
authors.forename: David F
authors.initials: DF
authors.lastname: McCleary
authors.forename: Feng
authors.initials: F
authors.lastname: Yue
authors.forename: My D
authors.initials: MD
authors.lastname: Dang
authors.forename: Bing
authors.initials: B
authors.lastname: Ren
mesh_terms: D000818:Animals; D019175:DNA Methylation; D004622:Embryo, Mammalian / Q000378:metabolism*; D004742:Enhancer Elements, Genetic; D044127:Epigenesis, Genetic; D051379:Mice; D012045:Regulatory Sequences, Nucleic Acid; D017422:Sequence Analysis, DNA