Project description:In this study we used single cell multi-omics profiling to create an atlas of the human YS to gain insights into its haematopoietic, metabolic and nutritive functions during early embryonic development. This contains CITE-seq data (surface protein and cytosolic RNA content) data from two biological replicates. Pooled lanes were demultiplexed using SoupOrCell (for alignment and demultiplexing software and version numbers, please see accompanying manuscript and protocols within this accession). Raw count files provided are directly as output by alignment software, without any quality control applied. Quality control is described in accompanying manuscript methods. Metadata by barcode are provided as supplementary tables in accompanying manuscript.
Project description:Hematopoietic stem cell (HSC)-independent lymphopoiesis has been elucidated in murine embryos. However, our understanding regarding human embryonic counterparts remains limited. Here, we unveiled the presence of human yolk sac-derived lymphoid-biased progenitors (YSLPs) expressing CD34, IL7R, LTB and IRF8 at Carnegie Stage 10, much earlier than the first HSCs emergence. The number and lymphopoietic potential of these progenitors were both significantly higher in yolk sac than embryo proper at this early stage. Importantly, single-cell/bulk culture and CITE-seq have elucidated the tendency of YSLP differentiating into innate lymphoid cells and dendritic cells. Notably, lymphoid progenitors in fetal liver before and after HSCs seeding displayed distinct transcriptional features, with the former closely resembling those of YSLPs.
Project description:GW182 (Tnrc6a) is a key component of RISC (miRNA-Induced Silencing Complex) that plays a critical role in miRNA-mediated gene silencing. Here, we show that GW182 is expressed in the yolk sac endoderm, and that gene-trap disruption of GW182 leads to growth arrest of yolk sac endoderm, impaired hematopoiesis and embryonic lethality. To investigate roles of GW182 in the yolk sac endoderm, we assessed changes in mRNA expression in the yolk sac of E9.5 GW182gt/gt embryos using microarrays (Affymetrix).
Project description:GW182 (Tnrc6a) is a key component of RISC (miRNA-Induced Silencing Complex) that plays a critical role in miRNA-mediated gene silencing. Here, we show that GW182 is expressed in the yolk sac endoderm, and that gene-trap disruption of GW182 leads to growth arrest of yolk sac endoderm, impaired hematopoiesis and embryonic lethality. To investigate roles of GW182 in the yolk sac endoderm, we assessed changes in mRNA expression in the yolk sac of E9.5 GW182gt/gt embryos using microarrays (Affymetrix). Yolk sac of wild type littermates and GW182gt/gt embryos at E9.5 was collected for total RNA isolation using Trizol (Invitrogen). RNAs were purified according to the manufacturer’s protocol before subjected to Mouse Gene 1.0 ST Whole Genome Array (Affymetrix) for mRNA expression profiling. Experiments were performed in triplicate. Differentially expressed mRNAs were identified using a two-sample t-test (P<0.05 considered significant).
Project description:The human yolk sac (YS) is an extra-embryonic tissue critical for early prenatal life development. It is the first site of haematopoiesis where progenitors differentiate from endoderm within blood islands of the yolk sac contributing initially to primitive erythropoiesis and in subsequent waves to erythro-myeloid and lymphoid differentiation.
Project description:The human yolk sac (YS) is an extra-embryonic tissue critical for early prenatal life development. It is the first site of haematopoiesis where progenitors differentiate from endoderm within blood islands of the yolk sac contributing initially to primitive erythropoiesis and in subsequent waves to erythro-myeloid and lymphoid differentiation.
Project description:Transcriptional profiles of the embryonic yolk sac from embryos with ectopic Norrin expression were compared to their wild type littermate controls. The goal is to identify the transcriptional response to Norrin-Frizzled 4 signaling during embryonic angiogenesis.
Project description:Hematopoietic stem cell (HSC)-independent lymphopoiesis has been elucidated in murine embryos. However, our understanding regarding human embryonic counterparts remains limited. Here, we unveiled the presence of human yolk sac-derived lymphoid-biased progenitors (YSLPs) expressing CD34, IL7R, LTB and IRF8 at Carnegie Stage 10, much earlier than the first HSCs emergence. The number and lymphopoietic potential of these progenitors were both significantly higher in yolk sac than embryo proper at this early stage. Importantly, single-cell/bulk culture and CITE-seq have elucidated the tendency of YSLP differentiating into innate lymphoid cells and dendritic cells. Notably, lymphoid progenitors in fetal liver before and after HSCs seeding displayed distinct transcriptional features, with the former closely resembling those of YSLPs.
Project description:Primitive erythropoiesis in the mouse yolk sac is followed by definitive erythropoiesis resulting in adult erythrocytes. In comparison to definitive erythropoiesis little is known about the genes that control the embryonic erythroid program. The purpose of this study was to generate a profile of mouse embryonic yolk sac erythroid cells and identify novel regulatory genes differentially expressed in erythroid compared to non-erythroid (epithelial cells). The identification of these genes will contribute to a greater understanding of how the primitive erythroid program is controlled. This work will have clinical implications for treating sickle cell anemia and β-thalassemia. Activating genes in adult erythroid cells that increase embryonic or fetal globin gene expression may be a therapeutic approach to treat individuals with these disorders. Keywords: Comparison between mouse embryonic day 9.5 yolk sac microdissected primitive erythroid precursors and epithelial cells
Project description:Investigating the blood, immune and stromal cells present in a human fetal embryo in a world first single cell transcriptomic atlas. The embryo was dissected into 12 coronal sections, yolk sac, and yolk sac stalk. Live single cells sorted, with cell suspension then undergoing 10x chromium 5 prime scRNA-seq. This accession contains the yolk sac and yolk sac stalk data from this embryo. A matched accession contains the coronal section data. Lane "WS_wEMB12142156" (from yolk sac) was excluded from downstream analysis due to low fraction reads in cells post-CellRanger QC. Termination procedure for this embryo was medical. The F158_[features...barcodes...matrix].[tsv...mtx].gz files attached to this accession represent raw count data from all the 10x lanes in this accession combined, and as output from CellRanger filtered matrices (CellRanger version 6.0.1 using human reference genome GRCh38-2020-A). One set of count matrices relates to the yolk sac data, and one set of count matrices relates to the yolk sac stalk data.