Presence of cleaved caspase 3 in swine embryos of different developmental capacities produced by parthenogenetic activation

Abstract

This study assessed the presence of cleaved caspase 3 (CC3) during the in vitro development of swine embryos produced by parthenogenetic activation (PA). Embryos with high and low capacity to develop into blastocysts and the exposure to a caspase inhibitor (z-DEVD-fmk) were used to investigate the effect of CC3 on embryo development. The blastocyst rate (64.3% vs. 16.4%) and the average number of nuclei per blastocyst (39.7 vs. 19.8) were significantly higher (P < 0.05) in early- (before 24 hr) compared to late- (between 24 and 48 hr) cleaving embryos after PA. CC3 was mainly detected in the cytoplasm of Day-2 and -4 embryos, but was primarily localized in the nucleus of Day-5 and -6 embryos. The fluorescence signal for CC3 relative to negative controls was significantly higher (P < 0.05) in early- (2.42-fold) compared to late-cleaving (1.39-fold) embryos at Day 2 of culture. Treatment with z-DEVD-fmk during the first 24 or 48 hr of the culture period resulted in more embryos developing into blastocysts compared to the control group (55.8% and 55.1% vs. 37%, respectively; P < 0.05). This study confirmed the presence of CC3 in PA embryos from the two-cell to the blastocyst stage, and revealed that CC3 cellular-localization changed during embryo development. CC3 was shown to be more abundant in early-cleaving and more developmentally competent embryos compared to late-cleaving and less developmentally competent embryos. The inhibition of caspase activity at the beginning, but not at the end, of the culture period affected development of PA embryos.

Timing of first embryonic cleavage is a positive indicator of the in vitro developmental potential of porcine embryos derived from in vitro fertilization, somatic cell nuclear transfer and parthenogenesis

“…These findings confirm a limited number of reports detailing this phenomenon in early porcine IVF embryo development (Booth et al, 2007; Dang‐Nguyen et al, 2010) and SCNT embryo development (Jeon et al, 2011). Moreover, to our knowledge, this is only the second report demonstrating this trend in parthenogenetically activated oocytes of any species; see Coutinho et al (2011). This is an important finding as it suggests that at least some—if not all—of the major mechanistic components responsible for dictating developmental potential are inherently imbued in the mature MII oocyte, requiring no input from exogenous sources (e.g., spermatozoa or somatic nuclei).…”

Phosphorylated histone H2A.x in porcine embryos produced by IVF and somatic cell nuclear transfer

“…Moreover, we observed a higher proportion of nuclei with R10 foci in the 2-cell-stage embryos than in the 4-cell-stage embryos. It has been shown that fast-cleaving porcine embryos produce more and better-quality blastocysts than slow-cleaving embryos (Dang-Nguyen et al 2010, Coutinho et al 2011. Similarly, fast-developing porcine embryos produced by SCNT have a higher potential to support embryo development than slow-developing embryos (Isom et al 2012).…”

Effects of coculture with cumulus-derived somatic cells on in vitro maturation of porcine oocytes

“…The expression of POU5F1 is also an essential marker for early development in humans [46]. The other genes evaluated are involved in environmental stress, which is highly related to apoptosis and lower embryonic viability [47][48][49]. The mRNA levels of PCNA and POU5F1 were highly increased in IVF blastocysts from the 2.5 Â 10 4 and 5.0 Â 10 4 coculture groups.…”