Project description:Background: The transcriptional changes around the time of embryonic genome activation in pre-implantation embryos indicate that this process is highly dynamic. In vitro produced porcine blastocysts are known to be less competent than in vivo developed blastocysts. To understand the conditions that compromise developmental competence of in vitro embryos, it is crucial to evaluate the transcriptional profile of porcine embryos during pre-implantation stages. In this study, we investigated the transcriptome dynamics in in vivo developed and in vitro produced 4-cell embryos, morulae and hatched blastocysts. Results: In vivo developed and in vitro produced embryos displayed largely similar transcriptome profiles during development. Enriched canonical pathways from the 4-cell to the morula transition that were shared between in vivo developed and in vitro produced embryos included oxidative phosphorylation and EIF2 signaling. The shared canonical pathways from the morula to the hatched blastocyst transition were 14-3-3-mediated signaling, xenobiotic metabolism general signaling pathway, and NRF2-mediated oxidative stress response. The in vivo developed and in vitro produced hatched blastocysts were compared to identify molecular signaling pathways indicative of lower developmental competence of in vitro produced hatched blastocysts. A higher metabolic rate and expression of the arginine transporter SLC7A1 were found in in vitro produced hatched blastocysts. Conclusions: Our findings suggest that embryos with compromised developmental potential are arrested at an early stage of development, while embryos developing to the hatched blastocyst stage display largely similar transcriptome profiles, irrespective of the embryo source. The hatched blastocysts derived from the in vitro fertilization-pipeline showed an enrichment in molecular signaling pathways associated with lower developmental competence, compared to the in vivo developed embryos.
Project description:Temporal changes in the embryo transcriptome between the blastocyst stage (Day 7) and initiation of elongation (Day 13) differ between in vivo- and in vitro-derived embryos and are reflective of subsequent developmental fate. The aim of this study was to examine the temporal changes in transcriptional profile as the embryo develops from a spherical blastocyst on Day 7 to an ovoid conceptus at the initiation of elongation on Day 13 and to highlight differences in these temporal gene expression dynamics between in vivo- and in vitro-derived blastocysts which may be associated with embryonic survival/mortality using the bovine Affymetrix microarray. All embryos were produced either in vitro by IVF or in vivo by superovulation. A proportion of Day 7 blastocysts were snap frozen and the remainder were transferred (n=10 per recipient) to synchronized heifers, recovered on Day 13 and snap frozen individually. Three pools of Day 7 blastocysts (n=25 per pool for in vitro and in vivo, respectively) and three pools of Day 13 conceptuses (n=5 per pool, for in vivo and in vitro) were used for microarray. analysis.
Project description:Comparison of gene expression from expanded bovine blastocysts collected 7 days after fertilization and produced in vivo vs in vitro-SOF-OPU Two kinds of 7 days post fertilization bovine embryos, in-vivo 7 days blastocysts vs. In vitro 7 days blastocysts, Biological replicates: 4 in-vitro, 4 in-vivo, protocol,extract and semen shared. Dye swap.
Project description:Environmental estrogens may affect epigenetic programming as early as the period of preimplantation development. Therefore, we analyzed the effects of continuous gestational estradiol-17β (E2) exposure on male and female embryos. A low dose, close to the no-observed effect level (NOEL - 10 µg E2/kg body weight(bw)/d), a high dose (1000 µg E2/kg bw/d) and carrier only, as control group, was fed to sows from insemination until sampling at day 10 of pregnancy, respectively. 36 samples (n = 5-7 per treatment group and sex) were analyzed by high throughput sequencing.In the high dose group, RNA-sequencing of single embryos revealed 982 differentially expressed genes (DEG) in the female but none in the male blastocysts. Moreover, 62 and 3 DEG were found in female and male embryos of the NOEL dose group, respectively. Thus, maternal E2 treatment during early pregnancy affected gene expression of the embryos at day 10, potentially constituting the basis for long-term adverse effects.
Project description:Embryo transfer is largely used in cattle and classically performed at D7 (or D8) using unsorted D7 (or D8) blastocysts produced in vivo, or in vitro in defined media without serum or feeders. Outdated systems including serum and co-culture were however of interest for research purposes. We thus wondered whether embryos that would form a blastocoel at different times after fertilisation (D6 to D8) and stay in culture for up to 2 additional days (D6+1, D6+2, D7+1) would equally develop in vivo after temporary transfer to oestrus-synchronised recipients. Globally alike, those that survived up to D18 reached primitive streak stages and elongated to filamentous sizes similarly to in vivo (D18) or in vitro controls (classical D7-T7). Recovery rate differed between D6 and D8 embryos that were immediately transferred (58 vs 25% in D6-T6 vs D8-T8). With a reduced but intermediate survival (33%), the D6 embryos that stayed 2 more days in culture produced 7 times more IFN-tau at D18 than the immediately transferred D6 embryos. At the end of the culture, D6+2 embryos also displayed the higher number of differences with the D6 blastocysts. A “+1” phenotype emerged from the D6+1 and D7+1 embryos, that shared a larger gene set enrichment than the blastocysts they derived from, possible sign of a similar adaption to the in vitro environment. To the best of our knowledge, this is the first time that this culture system (B2, serum, co-culture) is used to study its impacts on the embryonic transcriptome prior to transfer. Initially reputed as beneficial to produce more expanding and hatching blastocysts, this culture system generated blastocysts that all dissembled in vivo developed ones (D7). Despite a loss of 40 to 60% in the two weeks after ET, no dying (vs surviving) signature was detectable in any of the transferred groups (D6, D6+2, D7+1, D8); was it rather a matter of developmental “pause”? Whether molecular differences prevailing to transfer partly reflected those induced by unfavourable conditions (or diapause) was therefore assessed.
Project description:In vitro culture of preimplantation mouse embryos is associated with changes in gene expression. It is however not known if the method of fertilization affects the global pattern of gene expression. We compared gene expression and development of mouse blastocysts produced in vitro (IVF), vs. blastocysts fertilized in vivo and cultured in vitro from the zygote stage (IVC), vs. control blastocysts flushed out of the uterus on post coital day 3.5. The global pattern of gene expression was assessed using the Affymetrix 430 2.0 chip.