English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Two different culture media (TCM-199 and follicular fluid), two activation treatments (10 and 50 micromol calcium ionophore l(-1)) and three culture periods with cycloheximide were evaluated to find effective culture conditions for activation of cumulus-free equine oocytes. Oocytes were collected by scraping the follicle walls of ovaries obtained from an abattoir. Oocytes with expanded cumuli were matured at 38.2 degrees C in a humidified atmosphere of 5% CO(2) in air, in either TCM-199 with 10% fetal bovine serum (FBS) and 5 microU FSH ml(-1), or in 100% follicular fluid derived from a preovulatory follicle 24 h after injection of hCG. After 40--42 h of in vitro maturation, oocytes were denuded by gentle pipetting in TCM-199 plus 10% FBS with hyaluronidase. Oocytes with intact cytoplasmic membranes (n = 398; 94% presumed metaphase II) were treated in protein-free PBS with 10 or 50 micromol calcium ionophore l(-1) for 5 min. After washing, the oocytes were cultured in TCM-199 containing 10% FBS and 10 microg cycloheximide ml(-1) for 6 h, in cycloheximide for 6 h and then in cycloheximide-free medium for 18 h, or in cycloheximide for 24 h. The oocytes were fixed and evaluated by fluorescence microscopy. Oocytes with pronucleus I--II (dense to decondensing chromatin), pronucleus III--IV (decondensed chromatin) or progressing towards the first cleavage division were considered activated. The activation rate for oocytes matured in TCM-199 was significantly (P < 0.05) higher than for oocytes matured in follicular fluid (49% (99/204) versus 35% (60/171), respectively; P < 0.05). Culture with cycloheximide for 24 h resulted in a significantly higher rate of activation (67%, 74/111) than did the 6 h (33%, 44/136) or 6 h plus 18 h (32%, 41/128) treatments. The highest rate of activation (82%) was observed in oocytes matured in TCM-199, treated with 50 micromol calcium ionophore l(-1) and cultured with cycloheximide for 24 h.

Activation of cumulus-free equine oocytes: effect of maturation medium, calcium ionophore concentration and duration of cycloheximide exposure