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The efficiency of in vitro embryo production in mammals is influenced by variables associated with culture conditions during maturation, fertilization, and embryonic development. The embryos obtained often exhibit low quality due to suboptimal in vitro culture conditions compared to the in vivo environment. Co-culturing gametes and embryos with somatic cells has been developed to enhance in vitro culture conditions. This study aimed to assess the impact of coculturing in vitro-produced porcine embryos with porcine oviductal epithelial cells (POEC) on embryo development and quality. Firstly, a pure culture of POEC suitable for coculture systems was established. The epithelial origin of the cells was confirmed by the expression of E-cadherin and cytokeratin. The expression pattern of hormone receptors aligned with the diestrous oviduct, and POEC also secreted oviductal glycoprotein type 1 (OVGP-1). Secondly, POEC from passage 1 (POEC-1) were used to coculture with in vitro-produced porcine embryos. A successful coculture system was established without the addition of fetal bovine serum as a supplement. Coculturing POEC-1 in monolayers with in vitro-produced porcine embryos during the initial two days of culture enhanced the percentage of blastocysts and their hatching. Although the coculture did not alter the number of cells in the blastocysts or apoptosis assessed by TUNEL, it significantly reduced reactive oxygen species (ROS) levels in cleaved porcine embryos. This study represents the first report evaluating the quality of porcine embryos produced by IVF in coculture systems and assessing ROS levels in cleaved porcine embryos obtained by IVF., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The molecule Dimethyl sulfoxide is widely used as drug solvent. However, its antioxidant property was poorly explored. In this study, we evaluated the effect of DMSO supplementation during oocyte in vitro maturation (IVM) on embryo development and quality. Bovine oocytes were matured with different DMSO concentrations (0, 0.1, 0.25, 0.5, 0.75, 1 and 10% v:v) followed by in vitro fertilization. Subsequently, quality indicators such as gene expression of SOX2, OCT4, CDX2, SOD1, oocyte and embryo redox status and DNA damage were evaluated. Polar body extrusion and blastocyst rates increased with 0.5% v:v DMSO. Moreover, first polar body extrusion and blastocyst rates did not increase with 1%, and 10% of DMSO reduced polar body extrusion and did not produce blastocyst. Optimal concentration of DMSO for the use on the maturation was estimated at around 0.45% v:v. Supplementation with 0.5% v:v DMSO has not affected mRNA abundance of genes key in blastocyst, however 0.75% increased gene expression of OCT4 and SOX2. Oocytes matured with 0.5% v:v DMSO and blastocyst from DMSO group showed reduced lipid peroxidation respect control. Total Glutathione concentrations increased in blastocyst stage in DMSO group. DMSO increased the total cell number of blastocysts but not TUNEL positive cells. In conclusion, our results suggest that low DMSO concentrations used during bovine oocytes in vitro maturation increases the maturation, as well as the blastocyst rate and its quality, without demonstrating deleterious effect on embryo cells., Competing Interests: Declaration of competing interest The authors declare no conflicts of interest., (Copyright © 2020 Elsevier Inc. All rights reserved.)