Oxygen tension modulates extracellular vesicles and its miRNA contents in bovine embryo culture medium.

The biotechnology for in vitro embryo production is becoming increasingly popular, being applied to humans and domestic animals. Embryo development can be achieved with either 20% or 5% oxygen tension. The extracellular vesicles (EVs) are secreted by different cell types and carry bioactive materials.

Antioxidant responses and deregulation of epigenetic writers and erasers link oxidative stress and DNA methylation in bovine blastocysts.

Early mammalian embryos derived from in vitro fertilization are exposed to conditions distinct from the native oviduct-uterine environment, including atmospheric oxygen that promotes cellular oxidative stress and alters gene expression. High oxygen partial pressure during embryo development is associated with low pregnancy rates and increased embryonic apoptosis. We investigated how bovine embryos responded to high (20%) or low (5%) oxygen partial pressure during in vitro culture, evaluating levels of reactive oxygen species (ROS) as well as changes in the expression of oxidative stress- and epigenetic-related transcripts and miRNAs in blastocysts.