title: DNA methylation in eukaryotes.
abstract: The DNA of higher eukaryotes contains one minor base, namely 5-methylcytosine. The distribution of this minor base between different species and different DNA fractions will be considered together with the actual sequences methylated. The properties of the enzyme responsible for DNA modification will be reviewed, particular note being paid to the efficiency of methylation of different DNA substrates. Various possible functions of the 5-methylcytosine in DNA will be considered and particular attention will be paid to the finding that specific modified bases present in DNA not undergoing transcription are absent in the same genes when these are being actively transcribed.
mesh_terms: D044503:5-Methylcytosine; D000375:Aging; D000818:Animals; D001374:Azacitidine / Q000494:pharmacology; D001483:Base Sequence; D002843:Chromatin / Q000378:metabolism; D003596:Cytosine / Q000031:analogs & derivatives / Q000032:analysis; D004247:DNA / Q000378:metabolism*; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000378:metabolism; D004262:DNA Restriction Enzymes / Q000378:metabolism; D015257:DNA-Cytosine Methylases; D019003:Deoxyribonuclease HpaII; D005786:Gene Expression Regulation; D005914:Globins / Q000235:genetics; D008745:Methylation; D009690:Nucleic Acid Conformation; D010047:Ovalbumin / Q000235:genetics
chemical_list: D002843:Chromatin; D044503:5-Methylcytosine; D003596:Cytosine; D005914:Globins; D010047:Ovalbumin; D004247:DNA; C029641:DNA modification methylase HpaII; D015257:DNA-Cytosine Methylases; D004248:DNA (Cytosine-5-)-Methyltransferases; D004262:DNA Restriction Enzymes; D019003:Deoxyribonuclease HpaII; D001374:Azacitidine