title: Artificial activation of bovine and equine oocytes with cycloheximide, roscovitine, strontium, or 6-dimethylaminopurine in low or high calcium concentrations.
abstract: Knowledge on parthenogenetic activation of oocytes is important to improve the efficiency of nuclear transfer (NT) and intracytoplasmic sperm injection (ICSI) because artificial activation of oocyte (AOA) is an essential step to achieve embryo production. Although different procedures for AOA have been established, the efficiency of in vitro production of embryos remains low, especially in equines and Bos taurus bovines. In an attempt to improve the techniques of NT and ICSI in bovine and equine species, we tested different combinations of drugs that had different mechanisms of action for the parthenogenetic activation of oocytes in these animals. The oocytes were collected, in vitro matured for 24 to 30 h and activated artificially, in the presence of low or high concentrations of calcium, with combinations of calcium ionophore (ionomycin) with cycloheximide, roscovitine, strontium, or 6-dimethylaminopurine (6-DMAP). For assessment of activation rates, oocytes were stained with Hoechst 33342 and observed under an inverted microscope. We showed that all combinations of drugs were equally efficient in activating bovine oocytes, with the best results obtained when high concentrations of calcium were adopted. For equine oocytes, high concentrations of calcium were not beneficial for the parthenogenetic activation and the combination of ionomycin with either 6-DMAP or roscovitine was effective in inducing artificial activation of oocytes. We believe that our preliminary findings provide some clues for the development of a better AOA protocol to be used with these species.
authors: Department of Animal Reproduction,School of Veterinary Medicine and Animal Science,University of São Paulo (USP),Prof. Dr Orlando Marques de Paiva,87 Postal code: 05508 270-São Paulo/SP-Brazil.
authors: Claudia Barbosa
authors: CB
authors: Fernandes
authors: Department of Animal Reproduction and Veterinary Radiology,School of Veterinary Medicine and Animal Science,São Paulo State University (UNESP),Rubião Júnior District s/n.-Postal code: 18618-970-Botucatu-SP,Brazil.
authors: Liani Gasparini
authors: LG
authors: Devito
authors: Department of Animal Reproduction and Veterinary Radiology,School of Veterinary Medicine and Animal Science,São Paulo State University (UNESP),Rubião Júnior District s/n.-Postal code: 18618-970-Botucatu-SP,Brazil.
authors: Lilian Rigatto
authors: LR
authors: Martins
authors: Department of Animal Reproduction and Veterinary Radiology,School of Veterinary Medicine and Animal Science,São Paulo State University (UNESP),Rubião Júnior District s/n.-Postal code: 18618-970-Botucatu-SP,Brazil.
authors: Ieda Dala Pria
authors: ID
authors: Blanco
authors: Department of Animal Reproduction and Veterinary Radiology,School of Veterinary Medicine and Animal Science,São Paulo State University (UNESP),Rubião Júnior District s/n.-Postal code: 18618-970-Botucatu-SP,Brazil.
authors: João Ferreria
authors: JF
authors: de Lima Neto
authors: Endogin,Comandante João Ribeiro de Barros,Km 226,Bauru-SP,Brazil.
authors: Patricia Myakawa
authors: PM
authors: Tsuribe
authors: Department of Animal Reproduction,School of Veterinary Medicine and Animal Science,University of São Paulo (USP),Prof. Dr Orlando Marques de Paiva,87 Postal code: 05508 270-São Paulo/SP-Brazil.
authors: Camila Gabriela Pereria
authors: CG
authors: Gonçalves
authors: Department of Animal Reproduction and Veterinary Radiology,School of Veterinary Medicine and Animal Science,São Paulo State University (UNESP),Rubião Júnior District s/n.-Postal code: 18618-970-Botucatu-SP,Brazil.
authors: Fernanda
authors: F
authors: da Cruz Landim-Alvarenga
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D002417:Cattle; D002478:Cells, Cultured; D003513:Cycloheximide / Q000494:pharmacology*; D005260:Female; D006736:Horses; D059471:In Vitro Oocyte Maturation Techniques; D015759:Ionomycin / Q000494:pharmacology; D009865:Oocytes / Q000187:drug effects* / Q000502:physiology*; D010312:Parthenogenesis / Q000187:drug effects; D011687:Purines / Q000494:pharmacology*; D000077546:Roscovitine; D013324:Strontium / Q000494:pharmacology*
chemical_list: D011687:Purines; D000077546:Roscovitine; D015759:Ionomycin; C001020:N(6),N(6)-dimethyladenine; D003513:Cycloheximide; D000225:Adenine; D002118:Calcium; D013324:Strontium