Development of porcine embryos produced by IVM/IVF in a medium with or without protein supplementation: effects of extracellular glutathione
This study was designed to examine the effects of extracellular reduced glutathione on development of pig embryos, produced by in vitro maturation (IVM) and in vitro fertilisation (IVF), in a chemically defined North Carolina State University (NCSU) 23 medium or in NCSU 23 medium with bovine serum albumin (BSA). Microfilament distribution, as a marker of embryo quality, was also examined by immunocytochemical staining and confocal microscopy. When the inseminated oocytes were cultured in the defined medium containing 0-0.5 mM glutathione, blastocyst formation as observed only in the media with glutathione (8.5-16.0%). Increased numbers of blastomeres were observed in the blastocysts as the concentration of glutathione was increased (18.8±7.2 to 31.0±8.6). In NCSU 23 medium with 4 mg BSA/ml, addition of glutathione at concentrations of 0.125-0.5 mM significantly increased the proportions of oocytes that developed to blastocysts (39.2-52.5%) compared with the control (29.5%). However, no difference was observed in the average cell number in the blastocysts (41.9±15.6 to 49.1±15.5). There were no significant differences in the microfilament distribution in the embryos produced in the defined medium and in the BSA-containing medium. These results indicate that pig embryos produced by IVM/IVF can develop to the blastocyst stage in a defined medium. BSA and glutathione have a synergistic effect on pig embryo development.(Received September 26 2001)
(Accepted December 17 2001)
Key Words: Embryo development; Glutathione; Pig; Protein-free medium.
c1 All correspondence to: Dr Wei-Hua Wang, IVF Laboratory, One Blackstone Place, 1st Floor, Women and Infants Hospital of Rhode Island, Providence, RI 02903, USA. Tel: +1 (401) 274 1122, ext 7170. Fax: +1 (401) 453 7598. e-mail: firstname.lastname@example.org