Constitutive heterochromatin during mouse oogenesis: the pattern of histone H3 modifications and localization of HP1alpha and HP1beta proteins.
Mol Reprod Dev
; 75(2): 414-28, 2008 Feb.
Article
em En
| MEDLINE
| ID: mdl-17891782
ABSTRACT
Centromeres are the fragments of DNA that are responsible for proper chromosome segregation. They consist of centromeric chromatin surrounded by blocks of pericentric heterochromatin, playing an important role in centromere function. In somatic cells, the pericentric domains have a specific pattern of epigenetic modifications of core histones and contain specific pericentric proteins. These features are probably more important for the centromere function than the sequence of the centromeric DNA itself. In somatic cells, the HP1alpha and HP1beta proteins are indispensable for constitutive heterochromatin formation and maintenance. We have analyzed the localization of these proteins in the primordial, growing, fully-grown, and maturing mouse oocytes. Additionally, we have analyzed post-translational modifications of histone H3, which can influence HP1alpha and HP1beta association with the heterochromatin. We showed that the regions of constitutive heterochromatin have a distinct pattern of histone H3 acetylation and di-, and trimethylation of its lysine 9. We demonstrated that HP1beta protein was present in pericentric chromatin domains in primordial oocytes, growing (transcriptionally active) oocytes, and in fully-grown oocytes, and was released to the cytoplasm after germinal vesicle breakdown. In contrast, the HP1alpha was never detected in primordial oocytes, was first detected in pericentric heterochromatin in growing oocytes, dissociated from pericentric heterochromatin in fully-grown oocytes, and it was never detected in maturing oocytes. The presence of HP1alpha and HP1beta proteins on the heterochromatin of transcriptionally active oocytes and their absence in transcriptionally silent oocytes suggest that they are necessary for the repression of RNA synthesis in heterochromatin domains of transcribing oocytes.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Oócitos
/
Proteínas Cromossômicas não Histona
/
Histonas
Limite:
Animals
Idioma:
En
Revista:
Mol Reprod Dev
Assunto da revista:
BIOLOGIA MOLECULAR
/
MEDICINA REPRODUTIVA
Ano de publicação:
2008
Tipo de documento:
Article
País de afiliação:
Polônia
País de publicação:
EEUU
/
ESTADOS UNIDOS
/
ESTADOS UNIDOS DA AMERICA
/
EUA
/
UNITED STATES
/
UNITED STATES OF AMERICA
/
US
/
USA