Oviductal extracellular vesicles enhance porcine in vitro embryo development by modulating the embryonic transcriptome

Oviductal extracellular vesicles (oEVs) have been identified as important components of the oviductal fluid (OF) and pointed as key modulators of gamete/embryo-maternal interactions. Here, we aimed at determining the functional impact of oEVs on embryo development and embryonic transcriptome in porcine. Experiment 1 examined the effect of oEVs and OF on embryo development. In vitro produced embryos were cultured with oEVs or OF for 2 days (EV 0-2; OF 0-2) or 7 days (EV 0-7; OF 0-7) using an in vitro sequential system or without supplementation (control). Experiment 2 analysed the transcriptomic alterations of EV-treated embryos versus (vs.) control and the oEVs RNA cargo by RNA-sequencing. EV 0-2 treatment enhanced embryo development over time compared to other treatments. Different RNA expression profiles between EV 0-2 vs. control and EV 0-7 vs. control embryos were obtained, with 54 and 59 differentially expressed (DE) genes and 6 and 7 DE miRNAs, respectively. In oEV RNA cargo, 12,998 RNAs and 163 miRNAs were identified. Integrative analysis pointed to specific oEV components that might act as modulators of the embryonic transcriptome. Overall, the findings suggested that oEVs could be a potential strategy to improve porcine IVF outcomes, particularly by using EV 0-2 treatment.