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)

Produção de embriões em ovinos Morada Nova e Somalis Brasileira / Embryo production in Morada Nova and Somalis Brasileira ewes

Superovulatory response and embryo yield in 19 Morada Nova and 20 Somalis Brasileira ewes was analyzed. All animals were synchronized with the insertion of an intravaginal device (CIDR®) on Day 0, replaced by a new device on Day 7, which remained in place until Day 14 and superovulated with 133mg of porcine FSH (pFSH) in decreasing doses at 12h intervals from Day 12 until Day 15 of the treatment, and a single dose of equine chorionic gonadotropin (eCG, 200UI) on Day 14 (i.e., administered in CIDR removal). Fifty hours after CIDR® removal, females were inseminated by laparoscopy. All embryos were recovered by laparotomy 5 days after insemination. Sheep which responded to the superovulation protocol (P>0.05) included 74% of the Morada Nova ewes and 50% of the Somalis Brasileira ewes. Morada Nova showed better results (P<0.05) than Somalis Brasileira in number of ovulations (15.38 ± 5.24 vs. 10.56 ± 2.83), total structures (11.00 ± 7.55 vs. 3.33 ± 1.94) and embryo yields (6.79 ± 5.35 vs. 2.90 ± 2.18). Despite the high fertilization rate, degenerate embryo rate was high for both breeds, with an overall rate of 39% (57/145). In conclusion, superovulatory response and embryo yields in Morada Nova ewes were considered sufficient to justify the use of this procedure in genetic resources conservation programs. However, improvements to embryo quality and control of precocious regression of corpus luteum are necessary to produce better results in the MOET program, with minimal variations and maximum embryo yield in Morada Nova and Somalis Brasileira ewes.(AU)