Effect of growth factors, EGF and IGF-I, and estradiol on in vitro maturation of sheep oocytes.
The objective of these experiments was to determine the effect of exogenous addition of insulin-like growth factor-I (IGF-I, 100 ng/mL), epidermal growth factor (EGF, 10 ng/mL) and estradiol (E2, 100 ng/mL) to the maturation medium of sheep oocytes on their subsequent development in vitro. Addition of IGF-I to the maturation medium did not improve nuclear or cytoplasmic maturation of sheep oocytes at the concentration tested. However, EGF improved significantly the resumption of meiosis (84% oocytes in metaphase II stage after IVM vs. 59% in medium alone). Cleavage rate and blastocyst development rates were improved (P<0.01) after addition of EGF (60% and 29%, respectively), as compared with maturation in TCM 199 alone (39% and 19%, respectively), but remained lower than rates observed after maturation in complete medium containing follicular fluid (FF, 10%) and FSH (81% and 35%, respectively). No additive effect of EGF over FSH was observed during these experiments. Addition of FF to FSH containing maturation medium improved significantly both cleavage (P<0.001) and blastocyst rates (P<0.05). Addition of E2 to the IVM medium is not required when medium already contains FF. However, in defined conditions supplementation of maturation medium with E2 had a positive effect. These results suggest that EGF, FSH and E2 may play an important role in the nuclear and cytoplasmic maturation of sheep oocytes in vitro.
Guler
A
A
Institut National de la Recherche Agronomique, Physiologie de la Reproduction et des Comportements, Nouzilly, France.
Poulin
N
N
Mermillod
P
P
Terqui
M
M
Cognié
Y
Y
D000818:Animals; D001562:Benzimidazoles / Q000737:chemistry; D004815:Epidermal Growth Factor / Q000494:pharmacology* / Q000502:physiology; D004958:Estradiol / Q000494:pharmacology* / Q000502:physiology; D005260:Female; D005307:Fertilization in Vitro / Q000662:veterinary*; D005456:Fluorescent Dyes / Q000737:chemistry; D015571:Follicular Fluid / Q000502:physiology; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology* / Q000502:physiology; D008297:Male; D008540:Meiosis / Q000187:drug effects / Q000502:physiology; D008856:Microscopy, Fluorescence / Q000662:veterinary; D009865:Oocytes / Q000187:drug effects / Q000254:growth & development / Q000502:physiology*; D012756:Sheep / Q000502:physiology*
D001562:Benzimidazoles; D005456:Fluorescent Dyes; D004958:Estradiol; D004815:Epidermal Growth Factor; D007334:Insulin-Like Growth Factor I; C017807:bisbenzimide ethoxide trihydrochloride