Comparison of two media for transport of in vivo porcine embryo.

ALCÂNTARA-NETO AS; BRISKI O; RATNER L; FERNANDEZ-MARTÍN, RAFAEL; LA MOTTA, GASTON EMILIO; DANIEL F. SALAMONE

Lima

Congreso; Annual Conference of the International Embryo Technology Society, Savannah, Georgia, 10?13 January 2022; 2023

IETS

n recent years, zygote gene editing has become an important approach to produce edited piglets for biomedicine. However, obtaining porcine zygotes is still difficult due to polyspermy problems during IVF. Therefore, in vivo recovery of zygotes from synchronised, inseminated, and sacrificed sows is a useful technique as an alternative to IVF. The aim of this work was to compare in vitro embryo development using two different transport media: tyrode’s albumin lactate pyruvate medium buffered with HEPES (TALP-H) with 1% Penicillin-Streptomycin Fungizone, and porcine zygote medium (PZM-3) after in vivo embryo recovery. Briefly, a group of 10 sows were synchronised with 1,000 IU of recombinant PMSG (Foli-rec) injected 24 h after weaning. Then, 72 h after weaning, oestrus was checked and sows who showed oestrus signs were injected with 750 IU of human chorionic gonadotrophin (hCG) (Ovusyn). Finally, 12 h after hCG injection, sows were inseminated and transported to the slaughterhouse for their sacrifice 24 h after insemination. Embryos were collected by threading a needle (18 G) into the oviduct and flushed with 30 mL of tempered TALP-H three times. Flushed media were recovered into a 0.22 µM EM-CON filter. Embryos were counted under stereoscope loupe and transported to the laboratory in cryotubes with 3 mL of TALP-H or PZM-3 for 6 h at 32°C. Then, embryos were cultured in vitro in 50-µL drops of PZM-3 covered with mineral oil at 38.5°C and 5% O2. Blastocyst development was evaluated at Day 7 of embryo culture. Data were analysed by Fisher’s exact test and differences were considered significant at P < 0.05. 77.41% of the embryos transported in PZM-3 (n = 31), reached the blastocyst stage (n = 24) being significantly higher than the blastocyst rate obtained from those transported in TALP-H (n = 3/24, 12.5%). In conclusion, our results suggest that PZM-3 medium is superior to TALP-H for transportation of zygotes intended for subsequent blastocyst development.