Differential methylation of mitochondrial and nuclear DNA in cultured mouse, hamster and virus-transformed hamster cells. In vivo and in vitro methylation.

摘要: Abstract Information has been lacking as to whether mitochondrial DNA of animal cells is methylated. The methylation patterns and nuclear DNAs several mammalian cell lines have therefore compared by four methods: (1) in vivo transfer the methyl group from [methyl-3H]methionine; (2) incorporation [32P]orthophosphate a combination (2); (3) [3H]deoxycytidine; (4) vitro with 3H-labeled S-adenosylmethionine donor methylase preparations L nuclei. were mouse cells, BHK21 C13 , B4 (baby hamster kidney transformed Bryan strain Rouse sarcoma virus), PyY (BHK polyoma virus). bases separated chromatographically, using 5-methylcytosine, 6-methylaminopurine and, some cases, 7-methylguanine markers. Mitochondrial was found be significantly less methylated than respect 5-methylcytosine all types studied methods used. relative advantages disadvantages each method discussed. level that estimated one-fourth one-fourteenth various lines. content per circular molecule (mol. wt 10 × 106) about 12 methylcytosine residues for 24, 30 36 BHK, respectively. Relative cytosine residues, estimate one 500 L-cells. values are presumed maximal. other had highest both (3). No observed confluent cells. Evidence presence activity associated fractions obtained. This could distinguished cellular differential response mercaptoethanol. Radioactivity only 5-methyl-cytosine DNA.