5-methylcytosine is formed by the action of DNA methyltransferase[?] on CpG sites. It can undergo spontaneous deamination to form thymine.
... Contents 242 Centuries: 2nd century - 3rd century - 4th century Decades: 190s 200s 210s 220s 230s - 240s - 250s 260s 270s 28 ...