title: Effect of Temporary Meiotic Attenuation of Oocytes with Butyrolactone I and Roscovitine in Resistance to Bovine Embryos on Vitrification.
abstract: This study aimed to produce in vitro bovine embryos by the addition of two drugs, which is responsible for oocyte meiosis inhibition: roscovitine (ROS) and butyrolactone I (BL-I). Oocytes were recovered from slaughtered cows and matured in a commercial medium and maintained in a 5% CO2 atmosphere. Oocytes were maintained for 6 h in an in vitro maturation (IVM) medium containing ROS (12.5 μm), BL-I (50 μm) and association of drugs (ROS 6.25 μm and BL-I 25 μm). Oocytes were cultured for 18 h in an agent-free medium for the resumption of meiosis. After 24 h of maturation, oocytes were inseminated in the commercial in vitro fertilization (IVF) medium. Presumptive zygotes were cultured in SOFaa medium in a 5% CO2 atmosphere. On day 3, rate of cleavage was evaluated and on days 6 and 7, rate of blastocyst formation. BL-I and its association with the ROS increased the rates of cleavage and blastocyst formation (p < 0.05). The ROS alone was inefficient, impairing embryonic development, with low rates of blastocyst formation when compared to the control group and other treatments (p < 0.05). The embryos from BL-I and ROS+BL-I groups presented higher number of cells and lower rates of cellular apoptosis compared to other groups, either for the fresh or for post-thawing embryos. Embryos from ROS+BL-I group showed to be more resistant to the vitrification process, presenting a higher rate of embryonic re-expansion (p < 0.05). In conclusion, block of meiosis using BL-I or its association with ROS increased the rate of blastocyst formation, and the association of ROS+BL-I resulted in a better resistance to the embryo cryopreservation process.
authors.affiliation: Department of Animal Reproduction, School of Veterinary Medicine and Animal Science, Universidade Estadual Paulista - UNESP, Botucatu, São Paulo, Brazil.
authors.forename: R R D
authors.initials: RR
authors.lastname: Maziero
authors.affiliation: Department of Animal Reproduction, School of Veterinary Medicine and Animal Science, Universidade Estadual Paulista - UNESP, Botucatu, São Paulo, Brazil.
authors.forename: C R F
authors.initials: CR
authors.lastname: Guaitolini
authors.affiliation: Department of Animal Reproduction, School of Veterinary Medicine and Animal Science, Universidade Estadual Paulista - UNESP, Botucatu, São Paulo, Brazil.
authors.forename: D M
authors.initials: DM
authors.lastname: Paschoal
authors.affiliation: Center for Veterinary Health Sciences, Physiological Sciences, Oklahoma State University (OSU), Stillwater, OK, USA.
authors.forename: T
authors.initials: T
authors.lastname: Kievitsbosch
authors.affiliation: Department of Animal Reproduction, School of Veterinary Medicine and Animal Science, Universidade Estadual Paulista - UNESP, Botucatu, São Paulo, Brazil.
authors.forename: M D
authors.initials: MD
authors.lastname: Guastali
authors.affiliation: Department of Animal Reproduction, School of Veterinary Medicine and Animal Science, Universidade Estadual Paulista - UNESP, Botucatu, São Paulo, Brazil.
authors.forename: C N
authors.initials: CN
authors.lastname: Moraes
authors.affiliation: Department of Animal Reproduction, School of Veterinary Medicine and Animal Science, Universidade Estadual Paulista - UNESP, Botucatu, São Paulo, Brazil.
authors.forename: F C
authors.initials: FC
authors.lastname: Landim-Alvarenga
mesh_terms: D015107:4-Butyrolactone / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D002417:Cattle / Q000196:embryology*; D059447:Cell Cycle Checkpoints / Q000187:drug effects; D004359:Drug Therapy, Combination; D046149:Embryo Culture Techniques / Q000662:veterinary*; D008540:Meiosis / Q000187:drug effects*; D047428:Protein Kinase Inhibitors / Q000008:administration & dosage / Q000494:pharmacology*; D011687:Purines / Q000008:administration & dosage / Q000494:pharmacology*; D000077546:Roscovitine
chemical_list: D047428:Protein Kinase Inhibitors; D011687:Purines; D000077546:Roscovitine; C082868:butyrolactone I; D015107:4-Butyrolactone