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:Human pre-implantation embryonic development involves extensive changes in chromatin structure and transcriptional activity. Here, we report on LiCAT-seq, a technique that enables simultaneous profiling of chromatin accessibility and gene expression with ultra-low input of cells, and map the chromatin accessibility and transcriptome landscapes for human pre-implantation embryos. We observed global difference in chromatin accessibility between sperm and all stages of embryos, finding that the accessible regions in sperm tend to occur in gene-poor genomic regions. Integrative analyses between the two datasets reveals strong association between the establishment of accessible chromatin and embryonic genome activation (EGA), and uncovers transcription factors and endogenous retrovirus (ERVs) specific to EGA. In particular, a large proportion of the early activated genes and ERVs are bound by DUX4 and become accessible as early as the 2- to 4-cell stages. Our results thus offer mechanistic insights into the molecular events inherent to human pre-implantation development.
Project description:Adult female mice (C57BL/6) were super-ovulated by intraperitoneal hormone injections with the interval of 48 hours between injections. The hormones administered were PMSG followed by hCG (5IU/0.1ml, Sigma-Aldrich). Following the second hormonal treatment, the females were mated with males (1:1, C57BL/6). Zygotes, 2-cell and 4-cell and blastocysts were collected 26, 48 and 52 hours post hCG. Prior to cell collection, the zona pelucida was removed by Tyrode s acid solution. The 2- and 4-cell embryos were then immersed in Trypsin solution (Invitrogen) with RNase inhibitor (1 IU/ul, Clontech) and BSA (50 ug/ul) for the separation of the blastomeres. The separated blastomeres were snap frozen, and maintained at -80 C until processed. Twelve zygotes, 20 2-cell and 9 4-cell embryos were collected for single cell qPCR. In addition, we prepared with a pool of 10 zygotes and a pool of 50 zygotes as positive controls. The cells and pools were subjected to reverse transcription with SuperScript VILO cDNA Synthesis kit (Life Technologies) as recommended by the manufacturer. DELTAgene Assays were custom designed for 94 genes associated with embryonic development or regulation of gene expression, as well as 2 housekeeping genes. The cDNA from cells and pools were subjected to target specific amplification for 20 cycles. Pre-amplified template was diluted and subjected to primer specific amplification with SooFast EvaGreen Supermix (Biorad) on 96.96 array chip and BiomarkHD System (Fluidigm). Relative quantification of gene expression (log2 space) was obtained by subtracting the Ct values from the baseline value of 22.
Project description:Adult female mice (C57BL/6) were super-ovulated by intraperitoneal hormone injections with the interval of 48 hours between injections. The hormones administered were PMSG followed by hCG (5IU/0.1ml, Sigma-Aldrich). Following the second hormonal treatment, the females were mated with males (1:1, C57BL/6). Zygotes, 2-cell and 4-cell and blastocysts were collected 26, 48 and 52 hours post hCG. Prior to cell collection, the zona pelucida was removed by Tyrode s acid solution. The 2- and 4-cell embryos were then immersed in Trypsin solution (Invitrogen) with RNase inhibitor (1 IU/ul, Clontech) and BSA (50 ug/ul) for the separation of the blastomeres. The separated blastomeres were snap frozen, and maintained at -80 C until processed. Twelve zygotes, 20 2-cell and 9 4-cell embryos were collected for single cell qPCR. In addition, we prepared with a pool of 10 zygotes and a pool of 50 zygotes as positive controls. The cells and pools were subjected to reverse transcription with SuperScript VILO cDNA Synthesis kit (Life Technologies) as recommended by the manufacturer. DELTAgene Assays were custom designed for 94 genes associated with embryonic development or regulation of gene expression, as well as 2 housekeeping genes. The cDNA from cells and pools were subjected to target specific amplification for 20 cycles. Pre-amplified template was diluted and subjected to primer specific amplification with SooFast EvaGreen Supermix (Biorad) on 96.96 array chip and BiomarkHD System (Fluidigm). Relative quantification of gene expression (log2 space) was obtained by subtracting the Ct values from the baseline value of 22. 12 zygotes, 10 2-cell, and 9 4-cell mouse (C57BL/6) embryos were collected and multi-cell embryos were separated into blastomeres
Project description:To determine the effect of Zika virus infection on pre-implantation embryonic development, we performed single blastocyst RNA-Seq on MOCK and ZIKV infected embryos. ZIKV infection results in an increased risk of spontaneous abortion and poor intrauterine growth although the mechanisms underlying fetal loss remain undetermined. Little is known about the impact of ZIKV infection during the earliest stages of pregnancy, or pre- and peri-implantation, because most current studies of ZIKV infection in pregnancy models focus on post-implantation stages. Here, we demonstrate that trophectoderm cells of pre-implantation human and mouse embryos can be efficiently infected with ZIKV, and that trophectoderm can propagate virus causing cell death of neural progenitors. These findings were corroborated by our demonstration that hESC-derived trophectoderm cells are infected by ZIKV in a dose dependent manner. RNAseq of single blastocysts revealed key transcriptional changes in cellular and physiologic functions upon ZIKV infection, including nervous system development and function, prior to commitment to the neural cell lineage. Finally, the pregnancy rate of mice infected pre-implantation was > 50% lower than females infected at E4.5. These results demonstrate that pre-implantation ZIKV infection of trophectoderm leads to miscarriage or spontaneous abortion. Moreover, pre- and peri-implantation ZIKV infects trophectoderm cells that propagate virus over time causing cell death in neural progenitors. Cumulatively, these data demonstrate that vertical pre- and peri-implantation ZIKV infection of trophectoderm impairs fetal development and causes neural progenitor cell death, elucidating a previously unappreciated association of pre- and peri-implantation ZIKV infection and microcephaly.
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:It is essential for early human life that mucosal immunological responses to developing embryos are tightly regulated. An imbalance of the complement system is a common feature of pregnancy complications. We hereby present the first full analysis of the expression and deposition of complement molecules in human pre-implantation embryos. Thus, far, immunological imbalance has been considered in stages of pregnancy following implantation. We here show that complement activation against developing human embryos takes place already at the pre-implantation stage. Using confocal microscopy, we observed deposition of activation products on healthy developing embryos, which highlights the need for strict complement regulation. We show that embryos express complement membrane inhibitors and bind soluble regulators. These findings show that mucosal complement targets human embryos, and indicate potential adverse pregnancy outcomes, if regulation of activation fails. In addition, single-cell RNA sequencing revealed cellular expression of complement activators. This shows that the embryonic cells themselves have the capacity to express and activate C3 and C5. The specific local embryonic expression of complement components, regulators, and deposition of activation products on the surface of embryos suggests that complement has immunoregulatory functions and furthermore may impact cellular homeostasis and differentiation at the earliest stages of life.
Project description:Obesity is a global rising problem with epidemiological dimension. Obese parents can have programming effects on their offspring leading to obesity and associated diseases in later life. This constitutes a vicious circle. Epidemiological data and studies in rodents demonstrated differential programming effects in male and female offspring, but the timing of their developmental origin is not known. This study investigated if sex-specific programming effects of parental obesity can already be detected in the pre-implantation period. Diet induced obese male or female mice were mated with normal-weight partners and blastocysts were recovered. Gene expression profiling revealed sex-specific responses of the blastocyst transcriptome to maternal and paternal obesity. The changes in the transcriptome of male blastocysts were more pronounced than those of female blastocysts, with a stronger impact of paternal than of maternal obesity. The sperm of obese mice revealed an increased abundance of several miRNAs compared to lean mice. Our study indicates that sex-specific programming effects of parental obesity already start in the pre‑implantation period and reveals specific alterations of the sperm miRNA profile as mechanistic link to programming effects of paternal obesity. We used microarrays to analyze the transcriptomes of sex-sorted blastocysts of mice, with one parent (either mother or father) being obese at the time of conception and compared it to the transcriptome of blasocysts of peri-conceptionally lean parents.
Project description:The oviduct is a specialized organ playing crucial roles in the success of early reproductive events and it provides an optimal microenvironment for early embryonic development. However, changes in oviductal environment due to estrus synchronization and superovulation hormonal treatments and subsequent influence on embryos transcriptome profile are not yet investigated. For that, the objective of this study was to investigate differences in developmental rate and transcriptome profile of bovine blastocysts cultured under superovulation or synchronization oviductal environment. Influence of oviductal environment on transcriptome abundance of produced blastocysts was examined using the Affymetrix GeneChip Bovine Genome Array. Eighteen Simmental heifers were synchronized, superovulated and artificially inseminated, then nine of them were flushed at day 2 by transvaginal endoscopic means and 2-cell stage embryos were recovered and endoscopicaly transferred to only synchronized recipients. The remaining half of superovulated heifers and the synchronized recipients were flushed at day 7 to collect blastocysts which developed either in superovulated or synchronized oviduct