30 The importance of cumulus cells for the survival and timing of meiotic resumption of porcine oocytes vitrified at the immature stage
| Autor: | Hiroyuki Kaneko, Nguyen Viet Linh, Junko Noguchi, N. T. Hiep, Tamas Somfai, Thanh Quang Dang-Nguyen, Nguyen Thi Men, Bui Xuan Nguyen, Yuji Hirao, Kazuhiro Kikuchi |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Germinal vesicle
Embryo culture Reproductive technology Biology Oocyte Oogenesis Andrology Endocrinology medicine.anatomical_structure Reproductive Medicine Genetics medicine Animal Science and Zoology Folliculogenesis Molecular Biology Spermatogenesis Gametogenesis Developmental Biology Biotechnology |
| Zdroj: | Reproduction, Fertility and Development. 33:122 |
| ISSN: | 1031-3613 |
| Popis: | Previous research revealed that vitrification at the immature (the germinal vesicle, GV) stage triggers premature meiotic resumption in cumulus-enclosed porcine oocytes and causes a damage in gap junctions (Appeltant et al. 2017 Reprod. Fertil. Dev. 29, 2419-2429). However, the correlation between the two phenomena was not investigated yet. The present research was conducted to clarify whether premature meiotic resumption is caused by gap junction disruption and to assess the importance of cumulus cells for the survival of porcine oocytes vitrified at the GV stage. Cumulus–oocyte complexes (COCs) were collected from 3- to 6-mm antral follicles of slaughtered gilts. Immediately after collection, approximately half of them were denuded mechanically (DOs). In each replicate, groups of COCs and DOs were processed without vitrification (control groups). Treatment groups of COCs and DOs were vitrified on Cryotop sheets in a combination of 17.5% propylene glycol and 17.5% ethylene glycol and warmed in 0.4 M sucrose. The oocytes were then cultured for 22 h in a chemically defined porcine oocyte medium (POM) supplemented with 10 ng mL−1 epidermal growth factor, 10 IU mL−1 equine chorionic gonadotrophin, 10 IU mL−1 human chorionic gonadotrophin, and 1 mM dibutyryl cAMP. After culture, COCs were denuded and oocyte survival was assessed by morphological evaluation of membrane integrity under a stereo microscope. Then, live oocytes were fixed and stained with 1% orcein and nuclear status was evaluated under a phase-contrast microscope. The experiment was replicated 5 times. Data were analysed by ANOVA followed by Tukey’s multiple comparisons test. After vitrification and culture, the survival rate in the COC group was higher (P |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|