Project description:Embryonic genome activation (EGA) marks the onset of embryonic program and enables the transition toward the first lineage specification. However, the molecular features of EGA and the transcription factors (TFs) orchestrating this process remain unclear. Here, by performing single-cell RNA-seq on bovine embryos, we reveal that major EGA is asynchronously initiated among blastomeres at the 8-cell stage. Integrative analyses reveal distinctive protein accumulation compared to transcription and translation activation during bovine EGA. Furthermore, we investigate the role of SP1, a TF activated at the minor EGA stage, with motifs enriched in accessible chromatin during major EGA stage in bovine and human embryos. SP1 deficiency leads to morula arrest in bovine and impairs EGA in human embryos. Multi-omics analysis demonstrates that SP1 promotes early lineage gene expression by modulating nearby chromatin states in bovine and directly targets key EGA genes in human embryos. Together, our study delineates the dynamics of bovine EGA and uncovers the conserved and species-specific roles of SP1 in regulating EGA and early development in mammals.
Project description:Embryonic genome activation (EGA), a pivotal transcriptional event during preimplantation development, is accompanied by post-transcriptional regulation of maternal mRNAs. Disentangling the transcriptional output of the newly activated embryonic genome from concomitant post-transcriptional processing is important for decoding EGA dynamics.Here, using optimized low-input SLAM-seq (thiol(SH)-linked alkylation for the metabolic sequencing) in mouse embryos, we delineates the temporal hierarchy of EGA nascent transcription during mouse preimplantation embryogenesis and uncovers a mechanistic link between EGA and the first lineage specification, providing new insights into the regulatory architecture of early mammalian development.
Project description:Multilineage differentiation of human embryonic stem cells into three-dimensional (3-D) model, termed as progressed elongated embryoid bodies (peEBs), recapitulates crucial features of early human development, including cardio myogenesis and haematopoiesis. Characterisation of peEBs at transcriptome and protein levels at different stages of development to study embryonic haematopoiesis and endothelial-to-hematopoietic-transition (EHT) in vitro.
Project description:Small RNAs including microRNAs play a critical role at different stages of haematopoiesis. The study was designed to profile miRNA expression during human erythropoiesis.
Project description:Ikaros DNA binding proteins are important regulators of haematopoiesis and genetic deletion of Ikaros results in severe developmental disturbances, including delayed thymocyte differentiation and an early and complete block in B cell development. Although Ikaros ChIP-seq data are available for mouse thymocytes and human haematopoietic progenitors, it has not been achieved in B cell progenitors. The goal of this study was to identify Ikaros binding sites in pre-B cells to define Ikaros target genes which could explain the essential role of Ikaros proteins in B cell differentiation. We carried out chromatin immunoprecipitation and high throughput sequencing (ChIP-seq) with antibodies to the C-terminus of endogenous Ikaros in primary pre-B cells isolated from mouse fetal livers.
