β-Mercaptoethanol in culture medium improves cryotolerance of in vitro-produced bovine embryos

Abstract

Summary The objective of this study was to investigate the effects of adding β-mercaptoethanol (βME) to culture medium of bovine in vitro-produced (IVP) embryos prior to or after vitrification on embryo development and cryotolerance. In Experiment I, Day-7 IVP blastocysts were vitrified and, after warming, cultured in medium containing 0, 50 or 100 μM βME for 72 h. Embryos cultured in 100 μM βME attained higher hatching rates (66.7%) than those culture in 0 (47.7%) and 50 (52.4%) μM βME. In Experiment II, IVP embryos were in vitro-cultured (IVC) to the blastocyst stage in 0 (control) or 100 μM βME, followed by vitrification. After warming, embryos were cultured for 72 h (post-warming culture, PWC) in 0 (control) or 100 μM βME, in a 2 × 2 factorial design: (i) CTRL–CTRL, control IVC and control PWC; (ii) CTRL–βME, control IVC and βME-supplemented PWC; (iii) βME–CTRL, βME-supplemented IVC and control PWC; or (iv) βME–βME, βME-supplemented IVC and βME-supplemented PWC. βME during IVC reduced embryo development (28.0% vs. 43.8%) but, following vitrification, higher re-expansion rates were seen in βME–CTRL (84.0%) and βME–βME (87.5%) than in CTRL–CTRL (71.0%) and CTRL–βME (73.1%). Hatching rates were higher in CTRL–βME (58.1%) and βME–βME (63.8%) than in CTRL–CTRL (36.6%) and βME–CTRL (42.0%). Total cell number in hatched blastocysts was higher in βME–βME (181.2 ± 7.4 cells) than CTRL–CTRL (139.0 ± 9.9 cells). Adding βME to the IVC medium reduced development but increased cryotolerance, whereas adding βME to the PWC medium improved embryo survival, hatching rates, and total cell numbers.

Comparing the effect of using 2-Mercaptoethanol in the cell culture medium of different cell passages of human mesenchymal stem cells

“…The addition of 2-Mercaptoethanol in the cell culture medium was established 40 years ago, and it has not been updated by recent studies. In this study, we revealed that 2-Mercaptoethanol is not required for MSCs early passages, and the possible explanation is the ability of these cells at early passages to secrete enough antioxidants and growth factors to support their survival and proliferation [14,16,18]. As the passage number increases, the addition of 2-Mercaptoethanol can produce more positive outcomes and speed up the growth of MSCs by reducing the level of ROS that has been accumulated as MSCs passage increases.…”

“…Cells Medium was changed every other day, and cells were allowed to grow for 5 days. The final concentration of 2-Mercaptoethanol in the cell culture medium was 50µm [14,15] and was added each time the medium was changed for the cells. The cells that were grown in cell culture medium without (w/o) 2-Mercaptoethanol were considered the control group.…”

Current Advances in Bovine In Vitro Maturation and Embryo Production Using Different Antioxidants: A Review

“…De Mattos et al [ 45 ] investigated the effects of β-mercaptoethanol (βME) supplementation to the culture medium of bovine in vitro-produced (IVP) embryos before or after vitrification on embryo development and cryotolerance. There were two experiments held.…”