Effect of EGF on in vitro maturation of domestic cat oocytes.
The objective of this study was to evaluate the influence of different concentrations of epidermal growth factor (EGF) on in vitro maturation of domestic cat oocytes. A total of 444 cat oocytes were matured in MSOF (maturation synthetic oviductal fluid) in the presence of varying EGF concentrations: (1) MSOF (control); (2) MSOF+10 ng/mL EGF (EGF10); (3) MSOF+25 ng/mL EGF (EGF25); and (4) MSOF+50 ng/mL EGF (EGF50). After IVM, oocytes were in vitro fertilized to verify the effect of adding EGF on cytoplasmic maturation. Cleavage rate was recorded and noncleaving oocytes were stained with Hoechst 33258 and examined to determine nuclear maturation rate. Cleaved zygotes were cultured in vitro and embryo stages were evaluated on days 6 and 7. There was no difference among groups in the total number of oocytes reaching the metaphase II (MII) stage (P>0.05). The EGF25 group had the highest (P<0.01) blastocyst yield (37.5%) and developmental competence (60.9%). Cleavage rate and resulting morulae and blastocysts on day 6 for EGF25 group were higher (P<0.01) than control and EGF50 groups. Although EGF did not significantly enhance nuclear maturation rate, it had a dose-related positive effect on cytoplasmic maturation, since the oocyte's ability to cleave and reach the blastocyst stage was improved at 25 ng/mL, with intermediate improvement at 10 ng/mL, but 50 ng/mL had no significant benefit. In conclusion, the addition of EGF to the maturation medium enhanced cytoplasmic maturation of cat oocytes in vitro.
Merlo
Barbara
B
Veterinary Clinical Department, Obstetric-Gynecological Section, University of Bologna, via Tolara di Sopra 50, 40064 Ozzano Emilia (BO), Italy.
Iacono
Eleonora
E
Zambelli
Daniele
D
Prati
Francesca
F
Belluzzi
Stefano
S
D000818:Animals; D001755:Blastocyst / Q000502:physiology; D002415:Cats / Q000502:physiology*; D018920:Coculture Techniques / Q000662:veterinary; D003247:Conservation of Natural Resources / Q000379:methods; D047108:Embryonic Development / Q000187:drug effects* / Q000502:physiology; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D005260:Female; D005307:Fertilization in Vitro / Q000662:veterinary; D008297:Male; D008540:Meiosis / Q000502:physiology; D009865:Oocytes / Q000187:drug effects* / Q000502:physiology; D011247:Pregnancy; D011897:Random Allocation
D004815:Epidermal Growth Factor