Prevention of hatching of porcine morulae and blastocysts by liquid storage at 20 °C

Abstract

Vitrification is the ideal method for long-lasting storage of porcine embryos. However, both strict airline regulations for transport of liquid nitrogen dewars and the technical problems experienced when vitrified embryos are transferred using non-surgical procedures have led to the introduction of alternative storage methods, such as preserving embryos in liquid state. This study evaluated whether a pH-stable medium containing high concentrations of either foetal calf serum (FCS; 50%) or BSA (4%) combined with storage at temperatures of 17 °C or 20 °C maintained in vivo -derived morulae and blastocysts alive and unhatched (a sanitary requirement for embryo transportation) during 72 h of storage. Neither FCS nor BSA supplements were able to counteract the negative effect of low temperatures (17 °C) on embryonic survival after storage. At 20 °C, the protective effect of FCS or BSA depended on embryo stage. While FCS successfully arrested embryo development of only blastocysts, BSA arrested the development of both morulae and blastocysts. Over 80% of BSA arrested embryos restarted development by conventional culture and progressed to further embryonic stages, including hatching. In conclusion, porcine morulae and blastocysts can survive and remain unhatched during at least 72 h when stored at 20 °C in a BSA-containing medium.

Achievements and future perspectives of embryo transfer technology in pigs

“…In contrast, medium containing 4% BSA at 20°C arrested the development of both morulae and unhatched blastocysts for 72 hr. Furthermore, 80% of the arrested embryos resumed development in conventional culture and progressed to further embryonic stages, including hatching (Martinez et al., ). Although the results of these studies indicate that the liquid preservation of porcine embryos may be an alternative method to cryopreservation, further studies are needed to determine the potential of these embryos to develop to term after NsDU‐ET.…”

Viability and developmental potential of porcine blastocysts preserved for short term in a chemically defined medium at ambient temperature

“…The technical obstacles in using vitrified porcine embryos for embryo transfer have encouraged the development of alternative methods such as short‐term storage in a liquid state (Martinez et al., 2014). To date, several types of serum‐containing or BSA‐containing media have been used for the short‐term storage of porcine in vivo‐derived embryos (Martinez, Cambra, Nohalez, Parrilla, Roca, et al., 2019; Martinez, Cambra, Nohalez, Parrilla, Sanchez‐Osorio, et al., 2019). Storage temperature and medium have been suggested to play a vital role in the preservation of porcine embryos (Martinez et al., 2018; Pomar et al., 2004).…”

Intrauterine Infusion of TGF-β1 Prior to Insemination, Alike Seminal Plasma, Influences Endometrial Cytokine Responses but Does Not Impact the Timing of the Progression of Pre-Implantation Pig Embryo Development

“…Embryos with appropriate morphologies and development following the norms of the International Embryo Transfer Society [ 44 ] were considered viable. The developmental stages of the viable embryos were scored for statistical analysis, as previously described [ 45 ]: 1—compacted morulae (unidentifiable blastomeres in the periphery), 2—early or full blastocysts (embryos with an initial or easily visible blastocoel and an inner cell mass and discernible trophoblast), and 3—expanded or hatching/hatched blastocysts (blastocysts with an increased diameter and thinned, broken, or lost zona pellucida).…”