Hematopoiesis in mammalian embryos proceeds through three successive waves of hematopoietic progenitors. Since their emergence spatially and temporally overlap and phenotypic markers are often shared, the specifics regarding their origin, development, lineage restriction and mutual relationships have not been fully determined. The identification of wave-specific markers would aid to resolve these uncertainties. Here, we show that toll-like receptors (TLRs) are expressed during early mouse embryogenesis. We provide phenotypic and functional evidence that the expression of TLR2 on E7.5 c-kit+ cells marks the emergence of precursors of erythro-myeloid progenitors (EMPs) and provides resolution for separate tracking of EMPs from primitive progenitors. Using in vivo fate mapping, we show that at E8.5 the Tlr2 locus is already active in emerging EMPs and in progenitors of adult hematopoietic stem cells (HSC). Together, this data demonstrates that the activation of the Tlr2 locus tracks the earliest events in the process of EMP and HSC specification.

Childhood Leukaemia Investigation Prague 2nd Faculty of Medicine Charles University Prague Czech Republic

Czech Centre for Phenogenomics and Laboratory of Transgenic Models of Diseases Institute of Molecular Genetics of the Czech Academy of Sciences Prague Czech Republic

Department of Cell Biology Faculty of Science Charles University Prague Czech Republic

Institute Gustave Roussy PR1 INSERM U1170 Villejuif France

Laboratory of Cell and Developmental Biology Institute of Molecular Genetics of the Czech Academy of Sciences Prague Czech Republic

Laboratory of Genomics and Bioinformatics Institute of Molecular Genetics of the Czech Academy of Sciences Prague Czech Republic

Laboratory of Hematooncology Institute of Molecular Genetics of the Czech Academy of Sciences Prague Czech Republic

Laboratory of Immunobiology Institute of Molecular Genetics of the Czech Academy of Sciences Prague Czech Republic

Samuel Lunenfeld Research Institute Mount Sinai Hospital Toronto ON Canada

The Hospital for Sick Children Research Institute Toronto ON Canada

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Tober J, et al. The megakaryocyte lineage originates from hemangioblast precursors and is an integral component both of primitive and of definitive hematopoiesis. Blood. 2007;109:1433–1441. doi: 10.1182/blood-2006-06-031898. PubMed DOI PMC

Xu M-j, et al. Evidence for the presence of murine primitive megakarycytopoiesis in the early yolk sac. Blood. 2001;97:2016–2022. doi: 10.1182/blood.V97.7.2016. PubMed DOI

Ferkowicz MJ, et al. CD41 expression defines the onset of primitive and definitive hematopoiesis in the murine embryo. Development. 2003;130:4393–4403. doi: 10.1242/dev.00632. PubMed DOI

Palis J, Robertson S, Kennedy M, Wall C, Keller G. Development of erythroid and myeloid progenitors in the yolk sac and embryo proper of the mouse. Development. 1999;126:5073–5084. PubMed

Bertrand JY, et al. Three pathways to mature macrophages in the early mouse yolk sac. Blood. 2005;106:3004–3011. doi: 10.1182/blood-2005-02-0461. PubMed DOI

McGrath KE, et al. Distinct sources of hematopoietic progenitors emerge before HSCs and provide functional blood cells in the mammalian embryo. Cell Rep. 2015;11:1892–1904. doi: 10.1016/j.celrep.2015.05.036. PubMed DOI PMC

Boiers C, et al. Lymphomyeloid contribution of an immune-restricted progenitor emerging prior to definitive hematopoietic stem cells. Cell Stem Cell. 2013;13:535–548. doi: 10.1016/j.stem.2013.08.012. PubMed DOI

Frame JM, Fegan KH, Conway SJ, McGrath KE, Palis J. Definitive hematopoiesis in the yolk sac emerges from wnt-responsive hemogenic endothelium independently of circulation and arterial identity. Stem Cells. 2016;34:431–444. doi: 10.1002/stem.2213. PubMed DOI PMC

Muller AM, Medvinsky A, Strouboulis J, Grosveld F, Dzierzakt E. Development of hematopoietic stem cell activity in the mouse embryo. Immunity. 1994;1:291–301. doi: 10.1016/1074-7613(94)90081-7. PubMed DOI

Taoudi S, Medvinsky A. Functional identification of the hematopoietic stem cell niche in the ventral domain of the embryonic dorsal aorta. Proc. Natl Acad. Sci. USA. 2007;104:9399–9403. doi: 10.1073/pnas.0700984104. PubMed DOI PMC

Dzierzak E, Speck NA. Of lineage and legacy: the development of mammalian hematopoietic stem cells. Nat. Immunol. 2008;9:129–136. doi: 10.1038/ni1560. PubMed DOI PMC

Kumaravelu P, et al. Quantitative developmental anatomy of definitive haematopoietic stem cells/long-term repopulating units (HSC/RUs): role of the aorta-gonad-mesonephros (AGM) region and the yolk sac in colonisation of the mouse embryonic liver. Development. 2002;129:4891–4899. PubMed

Ema H, Nakauchi H. Expansion of hematopoietic stem cells in the developing liver of a mouse embryo. Blood. 2000;95:2284–2288. doi: 10.1182/blood.V95.7.2284. PubMed DOI

Christensen JL, Wright DE, Wagers AJ, Weissman IL. Circulation and chemotaxis of fetal hematopoietic stem cells. PLoS Biol. 2004;2:E75. doi: 10.1371/journal.pbio.0020075. PubMed DOI PMC

Chen MJ, Yokomizo T, Zeigler BM, Dzierzak E, Speck NA. Runx1 is required for the endothelial to haematopoietic cell transition but not thereafter. Nature. 2009;457:887–891. doi: 10.1038/nature07619. PubMed DOI PMC

Lancrin C, et al. The haemangioblast generates haematopoietic cells through a haemogenic endothelium stage. Nature. 2009;457:892–895. doi: 10.1038/nature07679. PubMed DOI PMC

Chen MJ, et al. Erythroid/myeloid progenitors and hematopoietic stem cells originate from distinct populations of endothelial cells. Cell Stem Cell. 2011;9:541–552. doi: 10.1016/j.stem.2011.10.003. PubMed DOI PMC

Gomez Perdiguero E, Geissmann F. Development and maintainance of resident macrophages. Nat. Immunol. 2016;17:2–8. doi: 10.1038/ni.3341. PubMed DOI PMC

Okuda T, van Deursen J, Hiebert SW, Grosveld G, Downing JR. AML1, the . Cell. 1996;84:321–330. doi: 10.1016/S0092-8674(00)80986-1. PubMed DOI

Yokomizo T, et al. Requirement of Runx1/AML1/PEBP2αB for the generation of haematopoietic cells from endothelial cells. Genes Cells. 2001;6:13–23. doi: 10.1046/j.1365-2443.2001.00393.x. PubMed DOI

Lugus JJ, Park C, Ma YD, Choi K. Both primitive and definitive blood cells are derived from Flk-1+ mesoderm. Blood. 2009;113:563–566. doi: 10.1182/blood-2008-06-162750. PubMed DOI PMC

Gomez Perdiguero E, et al. Tissue-resident macrophages originate from yolk-sac-derived erythro-myeloid progenitors. Nature. 2015;518:547–551. doi: 10.1038/nature13989. PubMed DOI PMC

Ginhoux F, et al. Fate mapping analysis reveals that adult microglia derive from primitive macrophages. Science. 2010;330:841–845. doi: 10.1126/science.1194637. PubMed DOI PMC

Sheng J, Ruedl C, Karjalainen K. Most tissue-resident macrophages except microglia are derived from fetal hematopoietic stem cells. Immunity. 2015;43:382–393. doi: 10.1016/j.immuni.2015.07.016. PubMed DOI

Akira S, Takeda K, Kaisho T. Toll-like receptors: critical proteins linking innate and acquired immunity. Nat. Immunol. 2001;2:675–680. doi: 10.1038/90609. PubMed DOI

Medzhitov R. Recognition of microorganisms and activation of the immune response. Nature. 2007;449:819–826. doi: 10.1038/nature06246. PubMed DOI

De Luca K, et al. The TLR1/2 agonist PAM3CSK4 instructs commitment of human hematopoietic stem cells to a myeloid cell fate. Leukemia. 2009;23:2063–2074. doi: 10.1038/leu.2009.155. PubMed DOI

Megias J, et al. Direct Toll-like receptor-mediated stimulation of hematopoietic stem and progenitor cells occurs in vivo and promotes differentiation toward macrophages. Stem Cells. 2012;30:1486–1495. doi: 10.1002/stem.1110. PubMed DOI

Nagai Y, et al. Toll-like receptors on hematopoietic progenitor cells stimulate innate immune system replenishment. Immunity. 2006;24:801–812. doi: 10.1016/j.immuni.2006.04.008. PubMed DOI PMC

Harju K, Glumoff V, Hallman M. Ontogeny of Toll-like receptors Tlr2 and Tlr4 in Mice. Pediatr. Res. 2001;49:81–83. doi: 10.1203/00006450-200101000-00018. PubMed DOI

Kaul D, et al. Expression of Toll-like receptors in the developing brain. PLoS ONE. 2012;7:e37767. doi: 10.1371/journal.pone.0037767. PubMed DOI PMC

Li Y, et al. Inflammatory signaling regulates embryonic hematopoietic stem and progenitor cell production. Genes Dev. 2014;28:2597–2612. doi: 10.1101/gad.253302.114. PubMed DOI PMC

Balounova J, et al. Toll-like receptors expressed on embryonic macrophages couple inflammatory signals to iron metabolism during early ontogenesis. Eur. J. Immunol. 2014;44:1491–1502. doi: 10.1002/eji.201344040. PubMed DOI

Pevny L, et al. Development of hematopoietic cells lacking transcription factor GATA-1. Development. 1995;121:163–172. PubMed

Lux CT, et al. All primitive and definitive hematopoietic progenitor cells emerging before E10 in the mouse embryo are products of the yolk sac. Blood. 2008;111:3435–3438. doi: 10.1182/blood-2007-08-107086. PubMed DOI PMC

Azzoni, E. et al. Kit ligand has a critical role in mouse yolk sac and aorta-gonad-mesonephros hematopoiesis. EMBO Rep.19, e45477 (2018). PubMed PMC

Boisset JC, et al. In vivo imaging of haematopoietic cells emerging from the mouse aortic endothelium. Nature. 2010;464:116–120. doi: 10.1038/nature08764. PubMed DOI

Zhou F, et al. Tracing haematopoietic stem cell formation at single-cell resolution. Nature. 2016;533:487–492. doi: 10.1038/nature17997. PubMed DOI

Scialdone A, et al. Resolving early mesoderm diversification through single-cell expression profiling. Nature. 2016;535:289. doi: 10.1038/nature18633. PubMed DOI PMC

Kierdorf K, Prinz M, Geissmann F, Gomez Perdiguero E. Development and function of tissue resident macrophages in mice. Semin. Immunol. 2015;27:369–378. doi: 10.1016/j.smim.2016.03.017. PubMed DOI PMC

Hoeffel G, et al. C-Myb(+) erythro-myeloid progenitor-derived fetal monocytes give rise to adult tissue-resident macrophages. Immunity. 2015;42:665–678. doi: 10.1016/j.immuni.2015.03.011. PubMed DOI PMC

Stremmel C, et al. Yolk sac macrophage progenitors traffic to the embryo during defined stages of development. Nat. Commun. 2018;9:75. doi: 10.1038/s41467-017-02492-2. PubMed DOI PMC

Adachi O, et al. Targeted disruption of the MyD88 gene results in loss of IL-1- and IL-18-mediated function. Immunity. 1998;9:143–150. doi: 10.1016/S1074-7613(00)80596-8. PubMed DOI

Takeuchi O, et al. Differential roles of TLR2 and TLR4 in recognition of gram-negative and gram-positive bacterial cell wall components. Immunity. 1999;11:443–451. doi: 10.1016/S1074-7613(00)80119-3. PubMed DOI

McKinney-Freeman S, et al. The transcriptional landscape of hematopoietic stem cell ontogeny. Cell Stem Cell. 2012;11:701–714. doi: 10.1016/j.stem.2012.07.018. PubMed DOI PMC

Espin-Palazon R, et al. Proinflammatory signaling regulates hematopoietic stem cell emergence. Cell. 2014;159:1070–1085. doi: 10.1016/j.cell.2014.10.031. PubMed DOI PMC

Sawamiphak S, Kontarakis Z, Stainier DY. Interferon gamma signaling positively regulates hematopoietic stem cell emergence. Developmental cell. 2014;31:640–653. doi: 10.1016/j.devcel.2014.11.007. PubMed DOI PMC

Nejepinska J, et al. dsRNA expression in the mouse elicits RNAi in oocytes and low adenosine deamination in somatic cells. Nucleic Acids Res. 2012;40:399–413. doi: 10.1093/nar/gkr702. PubMed DOI PMC

Sharan SK, Thomason LC, Kuznetsov SG, Court DL. Recombineering: a homologous recombination-based method of genetic engineering. Nat. Protoc. 2009;4:206–223. doi: 10.1038/nprot.2008.227. PubMed DOI PMC

Downs KM, Davies T. Staging of gastrulating mouse embryos by morphological landmarks in the dissecting microscope. Development. 1993;118:1255–1266. PubMed

Team, R. D. C. R.:A Language and Environment for Statistical Computing. the R Foundation for Statistical Computing (2011).

van der Maaten L, Hinton G. Visualizing Data using t-SNE. J. Mach. Learn. Res. 2008;9:2579–2605.

Fiser K, et al. Detection and monitoring of normal and leukemic cell populations with hierarchical clustering of flow cytometry data. Cytom. Part A: J. Int. Soc. Anal. Cytol. 2012;81:25–34. doi: 10.1002/cyto.a.21148. PubMed DOI

Nakano T, Kodama H, Honjo T. Generation of lymphohematopoietic cells from embryonic stem cells in culture. Science. 1994;265:1098–1101. doi: 10.1126/science.8066449. PubMed DOI

Ogawa M, et al. B cell ontogeny in murine embryo studied by a culture system with the monolayer of a stromal cell clone, ST2: B cell progenitor develops first in the embryonal body rather than in the yolk sac. EMBO. 1988;7:1337–1343. doi: 10.1002/j.1460-2075.1988.tb02949.x. PubMed DOI PMC

Jag1 insufficiency alters liver fibrosis via T cell and hepatocyte differentiation defects

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Lyl-1 regulates primitive macrophages and microglia development