The influence of cumulus cells during in vitro fertilization of buffalo (Bubalus bubalis) denuded oocytes that have undergone vitrification.
The aim of this work was to evaluate whether providing a support of cumulus cells during IVF of buffalo denuded oocytes submitted to vitrification-warming enhances their fertilizing ability. In vitro matured denuded oocytes were vitrified by Cryotop in 20% EG + 20% of DMSO and 0.5 M sucrose and warmed into decreasing concentrations of sucrose (1.25 M-0.3M). Oocytes that survived vitrification were fertilized: 1) in the absence of a somatic support (DOs); 2) in the presence of bovine cumulus cells in suspension (DOs+susp); 3) on a bovine cumulus monolayer (DOs+monol); and 4) with intact bovine COCs in a 1:1 ratio (DOs+COCs). In vitro matured oocytes were fertilized and cultured to the blastocyst stage as a control. An increased cleavage rate was obtained from DOs+COCs (60.9%) compared to DOs, DOs+susp (43.6 and 38.4, respectively; P < 0.01) and DOs+monol (47.5%; P < 0.05). Interestingly, cleavage rate of DOs+COCs was similar to that of fresh control oocytes (67.8%). However, development to blastocysts significantly decreased in all vitrification groups compared to the control (P < 0.01). In conclusion the co-culture with intact COCs during IVF completely restores fertilizing capability of buffalo denuded vitrified oocytes, without improving blastocyst development.
Attanasio
Laura
L
DISCIZIA, Faculty of Veterinary Medicine, Federico II University, Via F. Delpino 1, 80137 Naples, Italy.
De Rosa
Anna
A
De Blasi
Marina
M
Neglia
Gianluca
G
Zicarelli
Luigi
L
Campanile
Giuseppe
G
Gasparrini
Bianca
B
D000818:Animals; D002020:Buffaloes / Q000196:embryology*; D002417:Cattle; D018920:Coculture Techniques / Q000662:veterinary*; D015925:Cryopreservation / Q000662:veterinary*; D054885:Cumulus Cells / Q000502:physiology*; D046149:Embryo Culture Techniques; D047108:Embryonic Development; D005260:Female; D005307:Fertilization in Vitro / Q000662:veterinary*; D009865:Oocytes / Q000166:cytology*