SMC5/6 is required for the formation of segregation-competent bivalent chromosomes during meiosis I in mouse oocytes.
Development
; 144(9): 1648-1660, 2017 05 01.
Article
em En
| MEDLINE
| ID: mdl-28302748
ABSTRACT
SMC complexes include three major classes cohesin, condensin and SMC5/6. However, the localization pattern and genetic requirements for the SMC5/6 complex during mammalian oogenesis have not previously been examined. In mouse oocytes, the SMC5/6 complex is enriched at the pericentromeric heterochromatin, and also localizes along chromosome arms during meiosis. The infertility phenotypes of females with a Zp3-Cre-driven conditional knockout (cKO) of Smc5 demonstrated that maternally expressed SMC5 protein is essential for early embryogenesis. Interestingly, protein levels of SMC5/6 complex components in oocytes decline as wild-type females age. When SMC5/6 complexes were completely absent in oocytes during meiotic resumption, homologous chromosomes failed to segregate accurately during meiosis I. Despite what appears to be an inability to resolve concatenation between chromosomes during meiosis, localization of topoisomerase IIα to bivalents was not affected; however, localization of condensin along the chromosome axes was perturbed. Taken together, these data demonstrate that the SMC5/6 complex is essential for the formation of segregation-competent bivalents during meiosis I, and findings suggest that age-dependent depletion of the SMC5/6 complex in oocytes could contribute to increased incidence of oocyte aneuploidy and spontaneous abortion in aging females.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Oócitos
/
Proteínas de Ciclo Celular
/
Segregação de Cromossomos
/
Cromossomos de Mamíferos
/
Meiose
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Development
Assunto da revista:
BIOLOGIA
/
EMBRIOLOGIA
Ano de publicação:
2017
Tipo de documento:
Article
País de afiliação:
Estados Unidos