| Autor: |
Combelles, C. M. H., Cekleniak, N. A., Racowsky, C., Albertini, D. F. |
| Zdroj: |
Human Reproduction; Apr2002, Vol. 17 Issue 4, p1006-1016, 11p |
| Abstrakt: |
Background: With improved prospects for the use of human oocyte in-vitro maturation in assisted reproductive technologies, the need to define more clearly the coordination of nuclear and cytoplasmic maturation has arisen.Methods: Immunofluorescence and confocal microscopy were used to evaluate cell cycle-dependent modifications in chromatin and microtubules in human germinal vesicle oocytes (n = 455) undergoing in-vitro maturation.Results: Four distinct classes of germinal vesicle stage oocytes were identified based on the expression of G2/interphase characteristics, but, of these, only one class of oocytes was competent to complete meiotic progression to metaphase-II in vitro. The majority of germinal vesicle stage oocytes resumed meiosis within 6 h (88.9%) of culture and exhibited an accelerated pace of progression to metaphase-II (66.7%) over 24 h, but in general were unable to maintain meiotic arrest and defaulted into interphase within 24 h of polar body emission. Characterization of microtubule dynamics and chromatin phosphorylation demonstrates specific cell cycle deficiencies in in-vitro matured human oocytes.Conclusion: This work forms a basis for future studies aimed at optimizing nuclear and cytoplasmic maturation during in-vitro maturation. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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