Embryo aggregation regulates in vitro stress conditions to promote developmental competence in pigs

• Published in: PeerJ (San Francisco, CA) Vol. 7; p. e8143
• Main Authors: Jeong, Pil-Soo, Yoon, Seung-Bin, Lee, Mun-Hyeong, Son, Hee-Chang, Lee, Hwal-Yong, Lee, Sanghoon, Koo, Bon-Sang, Jeong, Kang-Jin, Lee, Jong-Hee, Jin, Yeung Bae, Song, Bong-Seok, Kim, Ji-Su, Kim, Sun-Uk, Koo, Deog-Bon, Sim, Bo-Woong
• Format: Journal Article
• Language: English
• Published: United States PeerJ. Ltd 13.12.2019; PeerJ, Inc; PeerJ Inc
• Subjects: Agricultural Science; Animal genetic engineering; Apoptosis; Biomedical research; Biotechnology; Blastocyst quality; Blastocysts; Cell Biology; Developmental Biology; Embryo; Embryogenesis; Embryonic development; Embryos; Endoplasmic reticulum; Endoplasmic reticulum stress; Gene expression; Genes; Genetic engineering; Hogs; In vitro fertilization; Metabolism; Mitochondria; Mitochondrial function; Pig embryo aggregation; Pluripotency; Polyvinyl alcohol; Reactive oxygen species; Sperm; Stem cells; Swine; Zoology; Japan; United States > US; Blastocyst quality; Reactive oxygen species; Mitochondrial function; Pig embryo aggregation; Endoplasmic reticulum stress
• ISSN: 2167-8359; 2167-8359
• DOI: 10.7717/peerj.8143

Embryo aggregation is a useful method to produce blastocysts with high developmental competence to generate more offspring in various mammals, but the underlying mechanism(s) regarding the beneficial effects are largely unknown. In this study, we investigated the effects of embryo aggregation using 4-cell stage embryos in developmental competence and the relationship of stress conditions in porcine early embryogenesis. We conducted aggregation using the well of the well system and confirmed that aggregation using two or three embryos was useful for obtaining blastocysts. Aggregated embryos significantly improved developmental competence, including blastocyst formation rate, blastomere number, ICM/TE ratio, and cellular survival rate, compared to non-aggregated embryos. Investigation into the relationship between embryo aggregation and stress conditions revealed that mitochondrial function increased, and oxidative and endoplasmic reticulum (ER)-stress decreased compared to 1X (non-aggregated embryos) blastocysts. In addition, 3X (three-embryo aggregated) blastocysts increased the expression of pluripotency, anti-apoptosis, and implantation related genes, and decreased expression of pro-apoptosis related genes. Therefore, these findings indicate that embryo aggregation regulates stress conditions to increase developmental competence and contributes to the production of high-quality embryos and the large-scale production of transgenic and chimeric pigs.