Morphokinetics of cloned mouse embryos treated with epigenetic drugs and blastocyst prediction

Abstract

Time-lapse monitoring of somatic cell nuclear transfer (SCNT) embryos may help to predict developmental success and increase birth and embryonic stem cells (ESC) derivation rates. Here, the development of ICSI fertilized embryos and of SCNT embryos, non-treated or treated with either psammaplin A (PsA) or vitamin C (VitC), was monitored, and the ESC derivation rates from the resulting blastocysts were determined. Blastocyst rates were similar among PsA-treated and VitC-treated SCNT embryos and ICSI embryos, but lower for nontreated SCNT embryos. ESC derivation rates were higher in treated SCNT embryos than in non-treated or ICSI embryos. Time-lapse microscopy analysis showed that non-treated SCNT embryos had a delayed development from the second division until compaction, lower number of blastomeres at compaction and longer compaction and cavitation durations compared with ICSI ones. Treatment of SCNT embryos with PsA further increased this delay whereas treatment with VitC slightly reduced it, suggesting that both treatments act through different mechanisms, not necessarily related to their epigenetic effects. Despite these differences, the time of completion of the third division, alone or combined with the duration of compaction and/or the presence of fragmentation, had a strong predictive value for blastocyst formation in all groups. In contrast, we failed to predict ESC derivation success from embryo morphokinetics. Time-lapse technology allows the selection of SCNT embryos with higher developmental potential and could help to increase cloning outcomes. Nonetheless, further studies are needed to find reliable markers for full-term development and ESC derivation success.

Prediction of blastocyst development and implantation potential <i>in utero</i> based on the third cleavage and compaction times in mouse pre-implantation embryos

“…Sensitivity and specificity are key parameters used to determine the accuracy and efficiency of diagnostic tests [58, 59]. In the context of the present study, sensitivity was defined as the proportion of embryos that developed successfully to the blastocyst and OG stages, whereas specificity was defined as the proportion of embryos that failed to reach these stages.…”

PsA inhibits the development of bovine embryos through epigenetic and oxidative stress

“…The final concentration of PsA was prepared by dilution of the stock solutions in the culture or activation media, depending on the experimental procedure. A starting PsA concentration of 5 μM was employed based on earlier reports, 9,28 and the embryos were divided into 3 groups by random: a control group and 2 treated groups (5 μM and 10 μM PsA, respectively). Embryos were exposed to PsA for 4 h for activation, subsequently cultured for 2 h or 8 h, and finally washed in drops of SOFaa culture medium.…”

Marine-Derived Natural Lead Compound Disulfide-Linked Dimer Psammaplin A: Biological Activity and Structural Modification

“…For the development of somatic cell nuclear transfer (SCNT) embryos, the embryonic stem cell (ESC)-derived rates from the obtained blastocysts and intracytoplasmic sperm injection (ICSI) fertilized embryos were determined with or without treatment of psammaplin A. The results showed that psammaplin A-treated SCNT exerted increased nuclear transfer ESC derivation and blastocyst rates, and further increased embryo delay, which was not necessarily related to the epigenetic effects [73].…”