Conceptual links between DNA methylation reprogramming in the early embryo and primordial germ cells.
Curr Opin Cell Biol
; 25(3): 281-8, 2013 Jun.
Article
en En
| MEDLINE
| ID: mdl-23510682
ABSTRACT
DNA methylation is a carrier of important regulatory information that undergoes global reprogramming in the mammalian germ line, including pre-implantation embryos and primordial germ cells (PGCs). A flurry of recent studies have employed technical advances to generate global profiles of methylation and hydroxymethylation in these cells, unravelling the dynamics of methylation erasure at single locus resolution. Active demethylation in the zygote, involving extensive oxidation, is followed by passive loss over early cell divisions. Certain gamete-contributed methylation marks appear to have evolved non-canonical mechanisms for targeted maintenance of methylation in the face of these processes. These protected sequences include the imprinting control regions (ICRs) required for parental imprinting but also a surprising number of other regions. Such targeted maintenance mechanisms may also operate at certain sequences during early PGC migration when global passive demethylation occurs. In later gonadal PGCs, imprints must be reset and this may be achieved through the targeting of active mechanisms including oxidation. Thus, emerging evidence paints a complex picture whereby active and passive demethylation pathways operate synergistically and in parallel to ensure robust erasure in the early embryo and PGCs.
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Metilación de ADN
/
Mamíferos
Límite:
Animals
Idioma:
En
Revista:
Curr Opin Cell Biol
Año:
2013
Tipo del documento:
Article
País de afiliación:
Reino Unido