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Nuclear and Cytoplasmic Maturation of Mouse Oocytes After Treatment with Synthetic Meiosis-Activating Sterol In Vitro1
- Source :
- Biology of Reproduction. 61:1362-1372
- Publication Year :
- 1999
- Publisher :
- Oxford University Press (OUP), 1999.
-
Abstract
- Synthetically produced meiosis-activating sterol, a sterol originally derived from follicular fluid (FF-MAS), induces meiotic maturation of mouse oocytes in vitro. We therefore compared FF-MAS-induced maturation of naked mouse oocytes arrested in prophase I by either hypoxanthine (Hx) or forskolin (Fo) with spontaneous maturation of naked oocytes. FF-MAS-treated oocytes overcame the meiotic block by Hx or Fo, although germinal vesicle breakdown was delayed by 11 h and 7 h, respectively. We also investigated the influence of FF-MAS on chromosome, microtubule, and ultrastructural dynamics in Hx-cultured oocytes by immunocytochemistry and electron microscopy. Similarly to spontaneously matured oocytes, chromosomes became aligned, a barrel-shaped spindle formed, and overall organelle distribution was normal in FF-MAS-matured oocytes. The number of small cytoplasmic asters was elevated in FF-MAS-treated oocytes. Although the number of cortical granules (CGs) was similar to that in spontaneously matured oocytes, the overall distance between CGs and oolemma was increased in the FF-MAS group. These observations suggest that the initiation of meiotic maturation in FF-MAS-treated oocytes in the presence of high cAMP levels leads to a delayed but otherwise normal nuclear maturation. FF-MAS appears to improve oocyte quality by supporting microtubule assembly and by delaying CG release, which is known to contribute to reduced fertilization.
- Subjects :
- musculoskeletal diseases
Genetics
Germinal vesicle
Forskolin
fungi
Cell Biology
General Medicine
Biology
Oocyte
Follicular fluid
Cell biology
chemistry.chemical_compound
medicine.anatomical_structure
Reproductive Medicine
Meiosis
chemistry
Microtubule
Cytoplasm
Organelle
medicine
lipids (amino acids, peptides, and proteins)
Subjects
Details
- ISSN :
- 15297268 and 00063363
- Volume :
- 61
- Database :
- OpenAIRE
- Journal :
- Biology of Reproduction
- Accession number :
- edsair.doi...........63c94e9a005d1b93aaae0a23370a7d24