Project description:At the moment of union in fertilization, sperm and oocyte are transcriptionally silent. The ensuing onset of embryonic transcription (embryonic genome activation, EGA) is critical for development, yet its timing and profile are unknown in any vertebrate species. We here dissect hitherto inaccessible transcription during EGA by high resolution single-cell RNA-sequencing of precisely synchronized mouse one-cell embryos. This reveals a program of embryonic gene expression (immediate EGA, iEGA) initiating within four hours of fertilization. Expression during iEGA produces canonically-spliced transcripts, occurs substantially from the maternal genome, and is mostly down-regulated at the two-cell stage. Transcribed genes predict regulation by transcription factors (TFs) associated with cancer, including c-Myc. Blocking c- Myc or other predicted regulatory TF activities disrupts iEGA and induces acute developmental arrest. These findings illuminate intracellular mechanisms that regulate the onset of mammalian development and promise a new paradigm for the study of cancer

2023-01-09 | GSE222130 | GEO

Functional effects of DNMT3A R882 on human haematopoietic stem and progenitor cells myeloid differentiation

Project description:This data presents the transcriptomes of bulk mature colonies derived from single human haematopoietic stem cells / multipotent progenitors (HSC/MPPs) and granulocyte macrophage progenitors (GMPs) purified from one indiviual with age related clonal haematopoisesis. The profiled colonies contain mature monocytes, as measured by conventional cell surface markers (CD14+, CD15-, GlyA-), but no other mature blood cell types. This dataset is part of a larger study, the main objective of which is to understand the functional effects conferred by somatic DNMT3A R882H mutation on human haematopoietic stem cell differentiation capacity. In clonal haematopoiesis, DNMT3A R882H and DNMT3A WT HSPCs co-exist in the same individual. We compared the transcriptional differences between mature monocytic colonies derived from DNMT3A R882H and WT HSPCs in vitro. Analysis of this dataset shows that, in this individual, DNMT3A R882H HSPCs produce less mature monocytes than their WT counterparts over the same culture time.

2023-08-28 | GSE241520 | GEO

Cell of origin epigenetic priming determines susceptibility to Tet2 mutation

Project description:Hematopoietic stem cell (HSC) mutations can result in clonal hematopoiesis (CH) with heterogeneous clinical outcomes. Here, we investigated how the cell state preceding Tet2 mutation impacts the pre-malignant phenotype. Using an inducible system for clonal analysis of myeloid progenitors, we found that the epigenetic features of clones at similar differentiation status were highly heterogeneous and functionally responded differently to Tet2 mutation. Cell differentiation stage also influenced Tet2 mutation response indicating that the cell of origin's epigenome modulates clone-specific behaviors in CH. Molecular features associated with higher risk outcomes include Sox4 that sensitized cells to Tet2 inactivation, inducing dedifferentiation, altered metabolism and increasing the in vivo clonal output of mutant cells, as confirmed in primary GMP and HSC models. Our findings validate the hypothesis that epigenetic features can predispose specific clones for dominance, explaining why identical genetic mutations can result in different phenotypes.

1970-01-01 | MTBLS9914 | MetaboLights

scRNAseq of immune cells of patients with chronic graft-versus-host disease

Project description:In this study, we investigated somatic mutations in T cells in patients with various hematological disorders. To analyze immune cell phenotypes with somatic mutations, we performed scRNA+TCRab sequencing from 9 patients with chronic GVHD and clonal expansions of CD4+ or CD8+ T cells based on T cell receptor sequencing. CD45+ PBMCs (lymphocytes and monocytes) were sorted with BD Influx cell sorter and subjected to sequencing with Chromium VDJ and Gene Expression platform (v1.1, 10X Genomics). Sequencing was performed with Novaseq 6000 (Illumina). The immune cell phenotypes were compared to healthy controls processed in the same laboratory (accession number E-MTAB-11170). Due to data privacy concerns, the raw sequencing data is in the European Genome-Phenome Archive (EGA) under accession code [xxxx] and can be requested through the EGA Data Access Committee.

2024-04-10 | E-MTAB-13419 | biostudies-arrayexpress

Mus musculus strain:C57BL/6

Project description:Clonal dynamics and somatic evolution of haematopoiesis in mouse

| PRJNA1033340 | ENA