title: Effect of different vitrification solutions and cryodevices on viability and subsequent development of buffalo oocytes vitrified at the germinal vesicle (GV) stage.
abstract: The cryopreservation of immature oocytes would generate a readily available, non-seasonal source of female gametes for research and reproduction. In domestic animals, the most promising results on oocyte cryopreservation have been reported in cattle, few studies have been conducted on buffalo. The aim of the present study was to compare the use of different vitrification solutions and various cryodevices on viability and developmental competence of buffalo oocytes vitrified at the germinal vesicle (GV) stage. Cumulus oocyte-complexes (COCs) obtained at slaughterhouse from mature buffalo ovaries were randomly divided into three main groups and vitrified by using either straw or open pulled-straw (OPS) or solid surface vitrification (SSV) in a solution composed of either 20% ethylene glycol (EG) + 20% glycerol (GLY); VS1 or 20% EG + 20% dimethylsulfoxide (DMSO); VS2, respectively. Following vitrification and warming, viable COCs were matured in vitro for 22 h. Some COCs were denuded and stained with 1.0% aceto-orcein to evaluate nuclear maturation, whereas the others were fertilized and cultured in vitro for 7 days to determine the developmental competence. Although the recovery rate (64.9%) was the lowest in the oocytes vitrified by SSV using 20% EG + 20% DMSO as compared to the other groups, the best survival rate of the COCs was achieved in the same treatment (96.7%), which was significantly higher (P < 0.05) than those vitrified using traditional straws (71.8% in VS1 and 73.6% in VS2) or those vitrified using OPS and VS1 (73.9%). Furthermore, in the nuclear maturation test, the highest maturation rate (75.5%) was achieved in SSV vitrified COCs using 20% EG + 20% DMSO (VS2), which was similar to the controls (77.1%). Post IVF and embryo culture, the highest cleavage and blastocyst development rates were obtained in COCs vitrified in 20% EG + 20% DMSO using SSV (47.1% and 24.0%, respectively), which showed no difference from the controls (61.2% and 46.9%, respectively). Our results clearly show that the combination of SSV and 20% EG + 20% DMSO could be used effectively to vitrify GV stage buffalo COCs.
authors.affiliation: Department of Theriogenology, Faculty of Veterinary Medicine, Cairo University, PO BOX 12211, Giza, Egypt.
authors.forename: Amr S
authors.initials: AS
authors.lastname: El-Shalofy
authors.affiliation: Department of Theriogenology, Faculty of Veterinary Medicine, Cairo University, PO BOX 12211, Giza, Egypt; Department of Surgery (Urology Division), Research Institute, McGill University Health Centre, Block E, Room S12363A, 1001 Decarie Blvd, Montreal, Quebec, H4A 3J1, Canada. Electronic address: adelreda902@hotmail.com.
authors.forename: Adel R
authors.initials: AR
authors.lastname: Moawad
authors.affiliation: Department of AI and ET, Animal Reproduction Research Institute, Agriculture Research Centre, Giza, Egypt.
authors.forename: Gamal M
authors.initials: GM
authors.lastname: Darwish
authors.affiliation: Department of Theriogenology, Faculty of Veterinary Medicine, Cairo University, PO BOX 12211, Giza, Egypt.
authors.forename: Sayed T
authors.initials: ST
authors.lastname: Ismail
authors.affiliation: Department of Theriogenology, Faculty of Veterinary Medicine, Cairo University, PO BOX 12211, Giza, Egypt.
authors.forename: Aly B A
authors.initials: ABA
authors.lastname: Badawy
authors.affiliation: Department of AI and ET, Animal Reproduction Research Institute, Agriculture Research Centre, Giza, Egypt.
authors.forename: Magdy R
authors.initials: MR
authors.lastname: Badr
mesh_terms: D000818:Animals; D002020:Buffaloes; D002417:Cattle; D002467:Cell Nucleus / Q000502:physiology; D015925:Cryopreservation / Q000379:methods / Q000662:veterinary*; D003451:Cryoprotective Agents / Q000494:pharmacology*; D004121:Dimethyl Sulfoxide / Q000494:pharmacology*; D047108:Embryonic Development / Q000187:drug effects; D019855:Ethylene Glycol / Q000494:pharmacology*; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods / Q000662:veterinary; D005990:Glycerol / Q000494:pharmacology*; D009865:Oocytes / Q000187:drug effects / Q000502:physiology*; D010078:Oxazines; D058989:Vitrification / Q000187:drug effects*
chemical_list: D003451:Cryoprotective Agents; D010078:Oxazines; C018437:aceto-orcein; D019855:Ethylene Glycol; D005990:Glycerol; D004121:Dimethyl Sulfoxide
keywords: Buffalo; Cryodevices; Cryoprotectants; Developmental competence; Germinal vesicle; Oocyte; Vitrification