'''5-Metilcitozin''' je [[metilacija|metilisana]] forma [[DNK]] baze [[citozin]]a. On može da učestvuje u regulaciji [[ТранскрипцијаTranskripcija (генетикаgenetika)|transkripcija]] gena. Kad je citozin metilisan, DNA zadržava istu sekvencu, dok [[Ekspresija gena|ekspresija metilisanih gena]] može da bude promenjena.<ref>{{cite journal |title = The rate of hydrolytic deamination of 5-methylcytosine in double-stranded DNA |author = Jiang-Cheng Shen, William M. Rideout III and Peter A. Jones |journal = Nucl. Acids Res. |year = 1994 |volume = 22 |issue = 6 |pages = 972-976 |doi = 10.1093/nar/22.6.972 |url = http://nar.oxfordjournals.org/content/22/6/972.short}}</ref><ref>{{cite journal |title = Recognition and estimation of 5-methylcytosine in nucleic acids |author = G. R. Wyatt |journal = Biochem J. |year = 1951 |volume = 48 |issue = 5 |pages = 581–584 |pmcid = 1275378 |url = http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1275378/}}</ref><ref>{{cite journal |title = Heat- and alkali-induced deamination of 5-methylcytosine and cytosine residues in DNA |author = Wang RY, Kuo KC, Gehrke CW, Huang LH, Ehrlich M |journal = Biochimica et Biophysica Acta |year = 1982 |volume = 697 |issue =3 |pages = 371-7 |doi = 10.1016/0167-4781(82)90101-4 |url = http://ukpmc.ac.uk/abstract/MED/7104364}}</ref> [[Epigenetika]] se bavi studiranjem ovih promena.<ref>{{cite journal |title = Epigenetic regulation of gene expression: how the genome integrates intrinsic and environmental signals |author = Rudolf Jaenisch & Adrian Bird |journal = Nature Genetics |volume = 33 |pages = 245-254 |year = 2003 |doi = 10.1038/ng1089 |url = http://www.nature.com/ng/journal/v33/n3s/full/ng1089.html}}</ref><ref>{{cite journal |title = Epigeneticgeneregulation by noncoding RNAs |author = Angela A Andersen, Barbara Panning |journal = Current Opinion in Cell Biology |volume = 15 |issue = 3 |year = 2003 |pages = 281–289 |doi = 10.1016/S0955-0674(03)00041-3 |url = http://www.sciencedirect.com/science/article/pii/S0955067403000413}}</ref>
== In vivo ==
5-Metilcitozin je [[Epigenetika|epigenetička modifikacija]] formirana dejstvom [[DNK metiltransferaza|DNK metiltransferaze]].
