DNA methylation in ciliates: implications in differentiation processes.
Much experimental evidence on the role of DNA methylation in gene expression has been reported. Here we review reports on DNA methylation in ciliated protozoa, emphasizing its implications in cell differentiation processes. Both types of methylated bases (adenine and cytosine) can be found in macronuclear DNA. The division cycle and conjugation have been studied with regard to adenine methylation, and several different functions have been assigned to the methylation changes detected in these processes. Cytosine methylation changes were analyzed during stomatogenesis of Paramecium and encystment of Colpoda inflata. A comparative analysis with other similar microbial eukaryotic differentiation processes is carried out.
Gutiérrez
J C
JC
Department of Microbiology-III, Faculty of Biology, Complutense University of Madrid, Spain. jgf00004@teleline.es
Callejas
S
S
Borniquel
S
S
Martín-González
A
A
D044503:5-Methylcytosine; D000225:Adenine / Q000031:analogs & derivatives / Q000032:analysis; D000818:Animals; D001374:Azacitidine / Q000494:pharmacology; D002454:Cell Differentiation / Q000235:genetics; D002467:Cell Nucleus / Q000502:physiology / Q000648:ultrastructure; D016798:Ciliophora / Q000166:cytology / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D003596:Cytosine / Q000031:analogs & derivatives / Q000032:analysis; D019175:DNA Methylation / Q000187:drug effects; D015254:DNA Modification Methylases / Q000502:physiology; D016054:DNA, Protozoan / Q000737:chemistry / Q000235:genetics*; D005786:Gene Expression Regulation; D018507:Gene Expression Regulation, Developmental; D010247:Paramecium / Q000166:cytology / Q000235:genetics / Q000378:metabolism; D015800:Protozoan Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology; D013768:Tetrahymena / Q000166:cytology / Q000235:genetics / Q000378:metabolism
D016054:DNA, Protozoan; D015800:Protozoan Proteins; C025946:3-methyladenine; D044503:5-Methylcytosine; D003596:Cytosine; D015254:DNA Modification Methylases; D000225:Adenine; D001374:Azacitidine