Maternal gamma (gamma)-tubulin is involved in microtubule reorganization during bovine fertilization and parthenogenesis.
Mol Reprod Dev
; 64(4): 438-45, 2003 Apr.
Article
em En
| MEDLINE
| ID: mdl-12589656
ABSTRACT
In this study, gamma-tubulin distribution was determined chronologically in conjunction with microtubule dynamics during bovine fertilization and parthenogenesis. In unfertilized bovine oocytes, gamma-tubulin was identified in the cytoplasm, mainly in the cortex and concentrated in the meiotic spindle. Following sperm penetration, gamma-tubulin in the cytoplasm was recruited by a sperm component. During pronuclear apposition, gamma-tubulin was localized as spots at the spindle poles. gamma-tubulin spots were observed in blastomeres of embryos cleaved in vitro. Following electrical stimulation, gamma-tubulin and microtubule matrix were noted in oocyte cortex. In the late pronuclear stage, considerably less gamma-tubulin and microtubules were detected in the cytoplasm. At the mitotic metaphase of parthenotes, gamma-tubulin was recruited to the condensed chromatin and concentrated in the spindle. The gamma-tubulin spots were not detected until the 8-cell stage of parthenotes. This suggests that maternal gamma-tubulin is recruited by a sperm component to reconstitute the zygotic centrosome. In the absence of sperm components, the cell cycle-related assembly of gamma-tubulin organizes microtubule nucleation for positioning the pronucleus and spindle protein of mitotic metaphase during the first cell cycle of bovine parthenotes.
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Base de dados:
MEDLINE
Assunto principal:
Partenogênese
/
Tubulina (Proteína)
/
Fertilização
/
Microtúbulos
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Ano de publicação:
2003
Tipo de documento:
Article