Biological aspects of cytosine methylation in eukaryotic cells

Experientia. 1991 Dec 1;47(11-12):1171-85. doi: 10.1007/BF01918381.


The existence in eukaryotes of a fifth base, 5-methylcytosine, and of tissue-specific methylation patterns have been known for many years, but except for a general association with inactive genes and chromatin the exact function of this DNA modification has remained elusive. The different hypotheses regarding the role of DNA methylation in regulation of gene expression, chromatin structure, development, and diseases, including cancer are summarized, and the experimental evidence for them is discussed. Structural and functional properties of the eukaryotic DNA cytosine methyltransferase are also reviewed.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Base Sequence
  • Cell Differentiation
  • Chromatin / chemistry
  • Chromatin / ultrastructure
  • Cytosine / metabolism*
  • DNA (Cytosine-5-)-Methyltransferases / physiology
  • DNA / metabolism*
  • Deoxyribonucleoproteins / chemistry
  • Eukaryotic Cells / metabolism*
  • Humans
  • Imprinting, Psychological
  • Methylation
  • Molecular Sequence Data
  • Promoter Regions, Genetic
  • Regulatory Sequences, Nucleic Acid


  • Chromatin
  • Deoxyribonucleoproteins
  • Cytosine
  • DNA
  • DNA (Cytosine-5-)-Methyltransferases