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:Pluripotent stem cells provide a platform to interrogate control elements that function to generate all cell types of the body. Despite their utility for modeling development and disease, the relationship of mouse and human pluripotent stem cell states to one another remains largely undefined. We have shown that mouse embryonic stem (ES) cells and epiblast stem cells (EpiSCs) are distinct, pluripotent states isolated from pre- and post-implantation embryos respectively. Human ES cells are different than mouse ES cells and share defining features with EpiSCs, yet are derived from pre-implantation human embryos. Here we show that EpiSCs can be routinely derived from pre-implantation mouse embryos. The pre-implantation-derived EpiSCs exhibit molecular features and functional properties consistent with bona fide EpiSCs. These results provide a simple method for isolating EpiSCs and offer direct insight into the intrinsic and extrinsic mechanisms that regulate the acquisition of distinct pluripotent states.
Project description:Pluripotent stem cells provide a platform to interrogate control elements that function to generate all cell types of the body. Despite their utility for modeling development and disease, the relationship of mouse and human pluripotent stem cell states to one another remains largely undefined. We have shown that mouse embryonic stem (ES) cells and epiblast stem cells (EpiSCs) are distinct, pluripotent states isolated from pre- and post-implantation embryos respectively. Human ES cells are different than mouse ES cells and share defining features with EpiSCs, yet are derived from pre-implantation human embryos. Here we show that EpiSCs can be routinely derived from pre-implantation mouse embryos. The pre-implantation-derived EpiSCs exhibit molecular features and functional properties consistent with bona fide EpiSCs. These results provide a simple method for isolating EpiSCs and offer direct insight into the intrinsic and extrinsic mechanisms that regulate the acquisition of distinct pluripotent states. 6 total samples were analyzed. Three pluripotent cell types (mES cells, E3.5 EpiSCs, and E5.5 EpiSCs) were compared with and without treatment of SB431542 for 4 days.
Project description:Comparison of the gene expression profiles of pre-implantation embryos at day 3.5 post coitum from normal pregnant mice (control); embryos from mice treated with ICI (specific estrogen receptor inhibitor); and embryos in the oviduct that were blocked from entering the uterus by ligation. Results provide insight into the function of estrogen regulated genes and uterine factors involved in the early implantation process.
Project description:Histone modifications play critical roles in regulating developmental genes expression during embryo development in mammals1,2. However, genome-wide analysis of histone modifications in pre-implantation embryos has been impeded by technical difficulties and the scarcity of required materials. Here, by using a small-scale chromatin immunoprecipitation sequencing (ChIP-seq) method3, for the first time, we mapped the genome-wide profile of histone H3 lysine 4 trimethylation (H3K4me3) and histone H3 lysine 27 trimethylation (H3K27me3), associated with gene activation and repression respectively, in mouse pre-implantation embryos. We found that the establishment of H3K4me3 mark occurs much more rapidly than that of H3K27me3 following fertilization. Furthermore, H3K4me3 and H3K27me3 possess distinct features in sequence preference and dynamics in pre-implantation embryos. Although most H3K4me3 signature constantly exists on transcription start site (TSS) region, the breadth of H3K4me3 domain is of high-dynamic feature. Interestingly, the broad H3K4me3 peak (wider than 5kb) is associated with higher transcription activity and cell identity not only in pre-implantation embryos but also in the process of deriving embryonic stem cells (ESCs) from the inner cell mass (ICM) and trophoblast stem cells (TSCs) from the trophectoderm (TE). Unlike those observed in ESCs, we found that the bivalency (containing both H3K4me3 and H3K27me3) is unstable and not frequently observed in early cleavage stage embryos until the morula to blastocyst transition. Taken all together, our study provides a genome-wide map of H3K4me3 and H3K27me3 modifications in pre-implantation embryos, which offers us opportunities to further understand the epigenetic regulation mechanism in early embryo development.
Project description:Comparison of the gene expression profiles of pre-implantation embryos at day 3.5 post coitum from normal pregnant mice (control); embryos from mice treated with ICI (specific estrogen receptor inhibitor); and embryos in the oviduct that were blocked from entering the uterus by ligation. Results provide insight into the function of estrogen regulated genes and uterine factors involved in the early implantation process. RNA were extracted from 3 groups of 100-120 embryos (a) embryos at d3.5 from uterus of normal pregnant mice; (b) embryos at d3.5 from uterus of ICI treated mice; and (c) embryos at d3.5 from the ligated oviduct.
Project description:Comparison of gene expression in in vivo derived pre-implantation porcine embryos in order to define molecular mechanisms involved in embryo development. Keywords: parallel sample
Project description:Comparison of gene expression in in vivo derived pre-implantation porcine embryos in order to define molecular mechanisms involved in embryo development. Keywords: parallel sample