The (adenine+thymine)/(guanine+cytosine) base ratios of 19 species of adriatic sponges have been determined by high-pressure liquid cation-exchange chromatography. The base ratios vary from 1.49 (Mycale massa) to 0.63 (Hippospongia communis) according to an (A+T) content of 59.7 and 38.6 mol%, respectively. The DNAs of sponges of the order Keratosa showed marked differences in their (A+T) conte...

The Ten-eleven translocation (TET) proteins have been recently identified as critical regulators in epigenetic modification, especially in the methylation of cytosine in DNA. TET-mediated DNA oxidation plays prominent roles in a wide variety of physiological and pathological processes, especially in tumor and neural development. TET proteins execute stepwise enzymatic conversion of 5-methylcyto...

A recent report in this journal [Vairapandi, M. and Duker, N.J. (1993) Nucleic Acids Res. 21, 5323-5327) presented evidence of an activity in HeLa cell nuclear extracts that released radiolabeled material from a poly(dG.dC) polymer that had been methylated and simultaneously labeled on cytosine residues by incubation with a CpG-specific DNA methylase and [methyl-3H]S-adenosylmethionine. Based o...

DNA methylation was measured in human tumor cell lines and freshly explanted pediatric tumors by [3H]uridine labeling followed by DNA hydrolysis and high-performance liquid chromatography. The percentage of cytosine residues modified to 5-methylcytosine in 4 cell lines derived from pediatric tumors was increased or similar to the levels of 3.45% found in two strains of diploid human fibroblasts...

DNA methylation plays an important role in the epigenetic regulation of mammalian gene expression. TET (ten-eleven translocation) proteins, newly discovered demethylases, have sparked great interest since their discovery. TET proteins catalyze 5-methylcytosine to 5-hydroxymethylcytosine, 5-formylcytosine and 5-carboxylcytosine in 3 consecutive Fe(II)- and 2-oxoglutarate (2-OG)-dependent oxidati...

The methylcytosine-containing sequences in the DNA of Bacillus subtilis 168 Marburg (restriction-modification type BsuM) were determined by three different methods: (i) examination of in vivo-methylated DNA by restriction enzyme digestion and, whenever possible, analysis for methylcytosine at the 5' end; (ii) methylation in vitro of unmethylated DNA with B. subtilis DNA methyltransferase and de...

The pyrimidine, 5-methylcytosine, was demonstrated by Wyatt (1) to be a component of plant and animal deoxyribonucleic acid.’ The deoxyriboside of 5-methylcytosine was isolated from wheat germ DNA by Dekker and Elmore (a), who also characterized this nucleoside. No microorganisms or viruses have yet been shown to contain this base, although the nucleic acids of many of these organisms have been...