title: 5-Methylcytosine in Chlorelle pyrenoidosa DNAs.
abstract: The presence of 5-methylcytosine in Chlorella pyrenoidosa (strain 211/8b) DNA's has been investigated by means of paper chromatography and thermal chromatography on hydroxyapatite. It has been shown that nuclear DNA contains 3.5 mol% 5-methylcytosine whereas no significant amount of this base can be detected in chloroplast DNA. The thermal chromatography of nuclear DNA labelled from [6-3H]- or [Me-14C] methionine lead us to conclude that the 5-methylcytosine content is directly proportional to the G + C content of the various DNA fractions. The existence of methylated sequences in DNA is postulated and the biological function of the 5-methylcytosine is discussed.
mesh_terms: D002467:Cell Nucleus / Q000378:metabolism; D002708:Chlorella / Q000378:metabolism*; D002845:Chromatography; D003596:Cytosine / Q000031:analogs & derivatives*; D004247:DNA / Q000378:metabolism*; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000378:metabolism; D006882:Hydroxyapatites; D009691:Nucleic Acid Denaturation
chemical_list: D006882:Hydroxyapatites; D003596:Cytosine; D004247:DNA; D004248:DNA (Cytosine-5-)-Methyltransferases