Phospholipid composition and resistance to vitrification of in vivo blastocyst of a Brazilian naturalized porcine breed / Composição de fosfolipídios e resistência à vitrificação de blastocistos produzidos in vivo de uma raça de suíno naturalizada brasileira

Piau porcine blastocysts were submitted to MALDI-TOF to identify the main phospholipids (PL). After that, in vivo blastocysts (D6) were vitrified (n=52), non-vitrified were used as control (n=42). After warming, blastocysts were in vitro cultured to assess re-expansion and hatching at 24 and 48 hours. Finally, at 48 hours, hatched blastocysts were submitted to RT-qPCR searching for BCL2A1, BAK, BAX and CASP3 genes. For MALDI-TOF, the ion intensity was expressed in arbitrary units. Blastocyst development was compared by Qui-square (P< 0.05). Among the most representative PL was the phosphatidylcholine [PC (32:0) + H]+; [PC (34:1) + H]+ and [PC (36:4) + H]+. Beyond the PL, MALDI revealed some triglycerides (TG), including PPL (50:2) + Na+, PPO (50:1) + Na+, PLO (52:3) + Na+ and POO (52:2) + Na. Re-expansion did not differ (P> 0.05) between fresh or vitrified blastocysts at 24 (33.3%; 32.7%) or 48 hours (2.4%; 13.5%). Hatching rates were higher (P< 0.05) for fresh compared to vitrified at 24 (66.7%; 15.4%) and 48 hours (97.6%; 36.0%). BAX was overexpressed (P< 0.05) after vitrification. In conclusion, Piau blastocysts can be cryopreserved by Cryotop. This study also demonstrated that the apoptotic pathway may be responsible for the low efficiency of porcine embryo cryopreservation.(AU)

Blastocistos de suínos foram submetidos ao MALDI-TOF para se identificarem os principais fosfolipídios (PL). Depois, parte destes embriões (D6) foram vitrificados (n=52), ou permaneceram frescos (grupo controle, n=42). Após o aquecimento, os blastocistos foram cultivados in vitro para se avaliar a reexpansão e a eclosão (BE) às 24 e 48 horas. Finalmente, às 48 horas, os BE foram submetidos ao RT-qPCR em busca dos genes BCL2A1, BAK, BAX e CASP3. No MALDI-TOF, a intensidade do íon foi expressa em unidades arbitrárias. O desenvolvimento embrionário foi comparado por qui-quadrado (P<0,05). Entre os PL mais representativos estavam as fosfatidilcolinas [PC (32: 0) + H] +; [PC (34: 1) + H] + e [PC (36: 4) + H] +. Além do PL, o MALDI revelou alguns triglicerídeos (TG), incluindo PPL (50: 2) + Na +, PPO (50: 1) + Na +, PLO (52: 3) + Na + e POO (52: 2) + Na. A reexpansão não diferiu (P>0,05) entre blastocistos frescos ou vitrificados às 24 (33,3%, 32,7%) e 48 horas (2,4%, 13,5%). As taxas de eclosão foram maiores (P<0,05) para o grupo fresco comparado ao vitrificado às 24 (66,7% x 15,4%) e 48 horas (97,6% x 36,0%). O BAX estava mais expresso (P<0,05) após a vitrificação. Concluindo, os blastocistos Piau podem ser criopreservados por Cryotop. Este estudo também demonstrou que a via apoptótica pode ser responsável pela baixa eficiência da criopreservação de embriões suínos.(AU)

Development of in vitro produced porcine embryos according to serum types as macromolecule

This study was conducted to establish an in vitro maturation (IVM) system by selection of efficient porcine serum during porcine in vitro production. To investigate the efficient porcine serum (PS), different types of PS [newborn pig serum, prepubertal gilt serum (PGS), estrus sow serum, and pregnancy sow serum] were used to supplement IVM media with or without gonadotrophin (GTH) and development rates of parthenogenetic activation (PA) and in vitro fertilization (IVF) embryos were then compared. The maturation rates of the PGS group was significantly higher when GTH was not added. Additionally, during development of PA embryos without GTH, the PGS group showed significantly higher cleavage and blastocyst formation rates. Moreover, the cleavage rates of IVF embryos were significantly higher in the PGS group, with no significant differences in the blastocyst formation. However, when GTH was supplemented into the IVM media, there were no significant differences among the four groups in the cleavage rates, development rates of the blastocyst, and cell number of the blastocyst after PA and IVF. In conclusion, PGS is an efficient macromolecule in porcine IVM, and GTH supplementation of the IVM media is beneficial when PS is used as macromolecule, regardless of its origin.