Project description:Much remains unknown about the signals that induce early mesoderm to initiate hematopoietic differentiation. Here we show that endoglin (Eng), a receptor for the TGFβ superfamily, identifies all cells with hematopoietic fate in the early embryo. These arise in an Eng+Flk1+ mesodermal precursor population at E7.5, a cell fraction also endowed with endothelial potential. In Eng knockout embryos, hematopoietic colony activity and numbers of CD71+Ter119+ erythroid progenitors were severely reduced. This coincided with severely reduced expression of embryonic globin and key BMP target genes including the hematopoietic regulators Scl, Gata1, Gata2 and Msx-1. To interrogate molecular pathways active in the earliest hematopoietic progenitors, we applied transcriptional profiling to sorted cells from E7.5 embryos. Eng+Flk-1+ progenitors co-expressed TGFβ and BMP receptors and target genes. Furthermore, Eng+Flk-1+ cells presented high levels of phospho-SMAD1/5, indicating active TGFβ and/or BMP signaling. Remarkably, under hematopoietic serum-free culture conditions, hematopoietic outgrowth of endoglin-expressing cells was dependent on TGFβ superfamily ligands: BMP4, BMP2, or TGF-β1. These data demonstrate that the E+F+ fraction at E7.5 represents mesodermal cells competent to respond to TGFb1, BMP4, or BMP2, shaping their hematopoietic development, and that endoglin is a critical regulator in this process by modulating TGF/BMP signaling. E7.5 pooled embryos (25 litters; 300 embryos approximately) were dissected and 3,000 cells were sorted in triplicate for Eng-Flk1-, Eng-Flk1+, Eng+Flk1+, and Eng+Flk1- fractions. Microarray results were analyzed with GeneSpring GX software.
Project description:Much remains unknown about the signals that induce early mesoderm to initiate hematopoietic differentiation. Here we show that endoglin (Eng), a receptor for the TGFβ superfamily, identifies all cells with hematopoietic fate in the early embryo. These arise in an Eng+Flk1+ mesodermal precursor population at E7.5, a cell fraction also endowed with endothelial potential. In Eng knockout embryos, hematopoietic colony activity and numbers of CD71+Ter119+ erythroid progenitors were severely reduced. This coincided with severely reduced expression of embryonic globin and key BMP target genes including the hematopoietic regulators Scl, Gata1, Gata2 and Msx-1. To interrogate molecular pathways active in the earliest hematopoietic progenitors, we applied transcriptional profiling to sorted cells from E7.5 embryos. Eng+Flk-1+ progenitors co-expressed TGFβ and BMP receptors and target genes. Furthermore, Eng+Flk-1+ cells presented high levels of phospho-SMAD1/5, indicating active TGFβ and/or BMP signaling. Remarkably, under hematopoietic serum-free culture conditions, hematopoietic outgrowth of endoglin-expressing cells was dependent on TGFβ superfamily ligands: BMP4, BMP2, or TGF-β1. These data demonstrate that the E+F+ fraction at E7.5 represents mesodermal cells competent to respond to TGFb1, BMP4, or BMP2, shaping their hematopoietic development, and that endoglin is a critical regulator in this process by modulating TGF/BMP signaling.
Project description:To identify Brachyury target genes in vivo and elucidate how Brachyury-mediated regulation contributes to early mouse developmental homeostasis and coordination, we performed mRNA-seq to compare gene expression profiles of WT and Tc/Tc embryos at both E7.5 ~ 8.0 and E10.0 ~ 10.5 WT and Tc/Tc embryos were isolated at both E7.5 ~ 8.0 and E10.0 ~ 10.5. Subsequently, directional mRNA-seq expriments were performed with wild-type and Tc/Tc whole embryos
Project description:We report the use of H3K27ac to pooled active enhancer elements during E7.5 mouse embryos. Our study is the first generated database derived from mouse E7.5 embryos, during late gastrula stages
Project description:Embryonic day (E)12.5 whole murine embryos, E11.5 - E14.5 whole murine embryos, E11.5 - E14.5, post-natal day (P)3 and P35 murine forelimbs, E14.5 brains, and COL1A2-mutant and COL1A2-WT forelimbs were fractionated and specific fractions were analyzed via LC-MS/MS. Aha-enrichment experiments consisted of in vivo protein labeling with azidohomoalanine (Aha) followed by tissue fractionation of the forelimbs and enrichment of labeled ECM proteins from the final IN pellet ('enriched'). 'Unenriched samples', or the background from which newly synthesized proteins were enriched from, were also analyzed via LC-MS/MS.
Project description:We identified distict mesodermal sub-populations based on Endoglin (Eng) and Flk1 expression in Brachyury (Bry) positive cells. By using whole-transcriptome analysis, we further characterized these populations and how they changed when Wnt pathway is inhibited
Project description:LV-EF1A-H2B-tdTomato-30N barcode virus was injected into the amniotic cavity (AC) of embryos at E7.5, using ultrasound guided in-utero nano-injections. E9.5 and E10.5 whole embryos were collected, dissociated, and sorted for tdTomato. Sorted cells were subjected to single cell RNA sequenced using 10X Genomics sequencing.
Project description:The experiment were perfomed as a part of our Vertebrate Evo-Devo project. The aim of the project is to compare transcription profiles of normal (unmanipulated, wild-type, whole embryo) vertebrate embryos. Total RNA was collected from wild type C57BL/6 mice, whole embryos at 8 different stages (Stages:E7.5, E8.5, E9.5, E10.5, E12.5, E14.5, E16.5, E18.5), and hybridized to A-AFFY-45 Mouse Genome 430 2.0 Array. All the stages contains data from 2 to 3 biological replications. Each staged-samples consists of pooled total RNA from several whole embryos.
