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In the present study, the timing was examined of blastocyst collection/formation or of how the duration of post-blastulation culture affected the quality and developmental competence of in vitro-produced pig parthenogenetic embryos. The earliest apoptotic signals were observed at the morula stage while the earliest cytoplasmic fragmentation was observed before the 4- to 8-cell stage of embryo development. Nuclear condensation was detected in morulae and blastocysts, but not all condensed nuclei were positive for the apoptotic signal (TUNEL staining). The mean blastocyst diameter increased with delayed blastocyst collection or extended post-blastulation culture, but decreased with delayed blastocyst formation. Delayed blastocyst collection/formation or an additional day of post-blastulation culture increased the frequencies of apoptosis, condensed nuclei, and low quality blastocysts (those showing a nuclear destruction that negated counting of the nuclei); increased the expression of the pro-apoptotic BAX gene; and reduced the ratio of ICM (inner cell mass) cells to TE (trophectoderm) cells. In addition, delayed blastocyst formation decreased POU5F1 gene expression. These results suggest that a delay in blastocyst collection/formation or an additional day of culture could increase the incidence of apoptosis, decrease the ICM:TE cell ratio, and influence the gene expression and diameter of blastocysts derived from in vitro-produced pig embryos. These findings provide a useful reference for improving the quality of in vitro-produced embryos.

The aim of this study is to investigate whether endoplasmic reticulum (ER) stress attenuation could improve porcine somatic cell nuclear transfer (SCNT) embryo developmental competence. We treated porcine SCNT embryos with TUDCA (tauroursodeoxycholic acid, an inhibitor of ER stress) and/or TM (tunicamycin, an ER stress inducer), and examined embryonic developmental potential, embryo quality, the levels of ER stress markers (XBP1 protein and mRNA) and apoptosis-related-genes (BAX and BCL2 mRNA). Immunostaining detected X-box-binding protein (XBP1), a key gene regulator during ER stress, at all stages of SCNT embryo development. Embryo development analysis revealed that TUDCA treatment markedly increased (p

In this study, we used a pig model to investigate the effects of α-solanine (a natural toxin found mainly in potato sprouts) on oocyte maturation, quality and subsequent embryonic development. We found that α-solanine (10 μM) disturbed meiotic resumption and increased abnormal spindle formation and altered the cortical granule (CG) distribution compared with the untreated group. α-Solanine triggered autophagy and apoptosis by increasing the expressions of autophagy-related genes (LC3, ATG7, and LAMP2) and apoptotic related genes (BAX and CASP3). Exposure of porcine oocytes to α-solanine significantly increased the levels of H3K36me3 and H3K27me3. Moreover, α-solanine significantly reduced the cleavage and blastocyst formation rates, decreased the total and inner cell mass cells numbers, and increased apoptosis in these porcine embryos. Taken together, our data indicate that α-solanine toxically impairs oocyte maturation and quality by triggering autophagy/apoptosis and facilitating epigenetic modifications. Furthermore, α-solanine suppressed subsequent embryonic development and reduced embryo quality.