Influence of parthenogenetic activation on nuclear maturation of canine oocytes.
This study was designed to evaluate the nuclear maturation and maturation promoting factor (MPF) level at different maturation times, and the effect of parthenogenetic activation on nuclear maturation in canine oocytes. Cumulus-oocyte complexes (COCs) were matured in TCM-199 supplemented with 10% fetal bovine serum, hormones, 0.57 mM cysteine, and 10 ng/ml epidermal growth factor for 72 hr at 38.5 degrees C. In Experiment 1, COCs at 0, 24, 48 and 72 hr of culture were assessed for nuclear maturation and MPF levels using histone H1 kinase activity assay. A significantly higher rate of oocytes at 72 hr than 0, 24 and 48 hr of culture developed to metaphase I-anaphase I and metaphase II. Relative abundance of histone H1 kinase activity of oocytes matured for 48 hr increased to ~1.5 x, with a marked increase to approximately 2.5 x for 72 hr, significantly higher than others. In Experiment 2, oocytes matured for 48 hr were parthenogenetically activated with 5 microm ionomycin for 5 min (Group 1) and followed by 10 microg/ml cycloheximide for 3 hr (Group 2), or no treatment (Control). Oocytes were then cultured for 24 hr and assessed for nuclear maturation. A significantly higher rate of oocytes in Group 1 developed to metaphase II than in Group 2 and the control. These results indicated that ionomycin treatment at 48 hr of in vitro maturation had a positive influence on oocyte progression to the metaphase II stage.
Song
Hye-Jin
HJ
Gyeongsang National University, Jinju, Republic of Korea.
Kang
Eun-Ju
EJ
Kim
Min-Jung
MJ
Ock
Sun-A
SA
Jeon
Byeong-Gyun
BG
Lee
Sung-Lim
SL
Rho
Gyu-Jin
GJ
D000818:Animals; D002417:Cattle; D018929:Cell Culture Techniques / Q000379:methods; D002467:Cell Nucleus / Q000502:physiology; D003513:Cycloheximide / Q000494:pharmacology; D004285:Dogs; D005260:Female; D006801:Humans; D015759:Ionomycin / Q000494:pharmacology; D008677:Metaphase; D009865:Oocytes / Q000166:cytology / Q000187:drug effects / Q000201:enzymology / Q000502:physiology*; D010312:Parthenogenesis / Q000187:drug effects / Q000502:physiology; D006656:Protamine Kinase / Q000378:metabolism; D012741:Sexual Maturation / Q000502:physiology
D015759:Ionomycin; D003513:Cycloheximide; D006656:Protamine Kinase