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. Author manuscript; available in PMC: 2019 Feb 2.
Published in final edited form as: Curr Opin Cell Biol. 2018 Feb 2;49:108–115. doi: 10.1016/j.ceb.2018.01.002

Tracking the Origin, Development, and Differentiation of Hematopoietic Stem Cells

Priyanka R Dharampuriya 1,2, Giorgia Scapin 1,2,3, Colline Wong 1,2,5, K John Wagner 1,2,5, Jennifer L Cillis 1,2,3, Dhvanit I Shah 1,2,3,4,*
PMCID: PMC5821519  NIHMSID: NIHMS934535  PMID: 29413969

Abstract

Purpose of review

The hierarchical nature of the hematopoietic system provides an ideal model system to illustrate the features of lineage tracing. We have outlined the utility of lineage tracing methods in establishing the origin and development of hematopoietic cells.

Recent findings

Methods such as CRISPR/Cas9, Polylox barcoding, and single-cell RNA-sequencing have improved our understanding of hematopoiesis.

Summary

This review chronicles the fate of the hematopoietic cells emerging from the mesoderm that subsequently develops into the adult blood lineages. Specifically, we explain classic techniques utilized in lineage tracing for the hematopoietic system, as well as novel state-of-the-art methods to elucidate clonal hematopoiesis and cell fate mapping at a single-cell level.

Keywords: Lineage tracing, Hematopoiesis, Hematopoietic stem cell, Blood, Cell fate mapping

INTRODUCTION

Hematopoiesis, or the process of blood formation, occurs in two waves. The primitive wave creates red blood cells and myeloid cells (1). The definitive wave begins with the formation of hematopoietic stem cells (HSC), followed by their development and differentiation into four adult blood lineages: erythroid, myeloid, platelet, and lymphoid cells (2). Given the hierarchal nature of hematopoiesis, it is an ideal process for establishing a foundation and then testing state-of-the-art methods in cell fate mapping.

Lineage tracing, a process of marking a single cell and following its progeny (3), establishes the origin, development, and differentiation of a cell by elucidating the identity, number, and location of its descendants (3). While cell transplantation, time-lapse confocal imaging, parabiosis, and genetic manipulation have established the hierarchical nature of blood formation, the development of quantitative processes and sequencing methods have recently uncovered the clonal nature of hematopoiesis.

Here, we illustrate how past and current advances in lineage tracing have uncovered the hierarchical and clonal nature of hematopoiesis.

LINEAGE TRACING IN HEMATOPOIESIS

a. Primitive and Definitive Hematopoiesis

The primitive wave of blood production in the yolk sac produces red blood cells and macrophages (1). This primitive wave is rapidly replaced by adult-type definitive hematopoiesis in the aorta-gonad-mesonephros (AGM) region (2). Here, a sheet of lateral mesoderm migrates medially, touches the endoderm, and forms a single aorta tube (4). Later, the clusters of hematopoietic stem cells emerge in the ventral wall of the dorsal aorta or the AGM region. Next, hematopoietic cells, which are capable of long-term reconstitution, colonize the fetal liver, thymus, spleen, and ultimately the bone marrow (5).

b. Extraembryonic Hematopoiesis

The first hematopoietic progenitors develop at embryonic day (E) 7.0 in the yolk sac (6). While hematopoietic activity also appears in umbilical arteries and the allantois (7), umbilical veins lack hematopoietic potential. This suggests that HSCs arise predominantly during artery specification. Although HSCs appear in the mouse placenta (8, 9), it is unclear whether placental HSCs arise de novo or through colonization upon circulation, or both.

c. Mesoderm to Hemangioblast

In the mouse embryo, the process of gastrulation generates the mesoderm at ~E6.5 (10). Here, the epiblast cells from the posterior part of the embryo form a transient primitive streak from which the mesoderm emerges. Then the mesoderm migrates away from the primitive streak, moves laterally and anteriorly, and is patterned into various populations with distinct developmental fates. Early mesodermal cells from the posterior primitive streak are the first source of blood islands in the embryo (11).

Brachyury, which is a transcription factor within the T-box complex of genes, marks all nascent mesodermal cells. As Brachyury+ cells undergo patterning and specification into the skeletal muscle, cardiac muscle, connective tissues, blood, and endothelium, its expression then diminishes (12–14).

The hemangioblast, a common precursor for endothelial and hematopoietic cells, is proposed as a site of hematopoiesis based on observations of chick blastoderms cultured in toto on coverslips (12) and explant cultures of the caudal region of blastoderms during the gastrulation stage. In both instances, hemangioblasts, which are aggregates of morphologically identical cells, produced endothelial cells and hematopoietic cells (12). However, fate mapping and chimera studies have failed to provide substantial evidence indicating that there was a common origin for endothelial and hematopoietic cells located in the early mouse yolk sac.

To determine the hematopoietic potential of individual cells in the mouse epiblast, primitive streak, and early yolk sac, Padrón-Barthe et al. (13) used an in vivo clonal analysis to demonstrate: (I) Early yolk sac blood and endothelial lineages derive from independent epiblast populations, specified before gastrulation. (II) A subpopulation of the yolk sac endothelium has hemogenic activity similar to that found later in the embryonic hemogenic endothelium (HE). (III) HE appears in the yolk sac and produces hematopoietic precursors with markers related to definitive hematopoiesis.

d. Hemangioblast to Hemogenic Endothelium

As hemangioblasts and HE develop near each other within the embryo, one hypothesis is that the hemangioblast generates HSCs through the formation of an HE intermediate (14). This is further supported by observations from single-cell-derived colonies that can produce both hematopoietic and endothelial cells in vitro. Utilizing the development of single-cell-resolution fate maps of the zebrafish late blastula and gastrula, Vogeli and colleagues (15) demonstrated that bipotential progenitors, which can give rise to both hematopoietic and endothelial cells, emerge along the entire lining of the ventral mesoderm. Their results provide in vivo evidence to support the existence of the hemangioblast.

Based on ES cell differentiation studies, the hemangioblast to hemogenic endothelium transition occurs in two stages. First, from 36–48 hours post-culture, a tight adherent structure arises from the hemangioblast. This is followed by the appearance of non-adherent round cells that proliferate to generate a mature blast colony then. However, it is unknown which mechanisms, if any, regulate or support the emergence of HE from hemangioblasts (14).

A morphological examination demonstrated that the AGM forms HE cells in the ventral wall of the aorta, instead of hemangioblasts that bud off to become HSCs. The program of HE cells development is regulated differently from that of presumptive hemangioblasts, as Runx1 is critical for HSC formation from the hemogenic endothelium but not from yolk sac hemangioblasts (16, 17).

e. Hemogenic Endothelium to Erythroid/Myeloid Progenitors (EMP) or Hematopoietic Stem Cells

The AGM is the first site of mammalian intra-embryonic hematopoiesis (18, 19). During E10.5–11.5, hematopoietic cells attached to the aorta bud off from this region (20). Imaging and lineage tracing studies in zebrafish embryos have established that the first HSCs emerge directly from hemogenic endothelium lining the ventral wall of the dorsal aorta (DA) (21, 22). These results complement previous studies in the avian, amphibian (21), and mammalian embryo (23) (24), which suggests that the cellular mechanisms of HSC generation are conserved across vertebrates.

Zovein et al. established that HSCs were generated from Cadherin 5 (Cdh5) precursors, suggesting that HSCs arise from the endothelium, and that AGM-derived endothelial cells contain the majority of HSC potential. As the conditional deletion of Runx1 in Cdh5+ cells led to the loss of HSCs, Runx1 is crucial in the transition from endothelium to HSC (25). However, Anderson et al. recently used state-of-the-art parabiosis and mouse chimera studies to establish that Cdh5 is dispensable for the formation, development, and differentiation of HSCs (22).

Before HSCs appear, committed erythroid/myeloid progenitors (EMPs) emerge from the yolk sac and the HE. The HE is located at sites of EMP and HSC emergence, such as the dorsal aorta, vitelline and umbilical arteries, yolk sac, and placenta. The HE is differentiated from all other endothelial cells by the presence of Runx1 (16). Runx1 is expressed in hemogenic endothelial cells before the formation of clusters, in the clusters themselves, and in all functional EMPs and HSCs (16, 17). Embryos lacking Runx1 have no EMPs, HSCs, or intra-arterial clusters (16, 17, 26). The utility of core binding factor β (CBFβ) for EMP and HSC formation is temporally and spatially distinct, and Ly6a explicitly marks the HSC-generating hemogenic endothelium (25).

f. HSC Development and Differentiation

HSCs differentiate into hematopoietic stem-progenitor cells (HSPC), which differentiate into multipotent progenitors (MPP). These multipotent progenitors lose their self-renewal capacity, but can still differentiate into all four adult hematopoietic lineages. The ability for HSCs to differentiate into progenitor cells, while also maintaining an adequate pool of HSCs via balancing self-renewal and differentiation, is essential for maintaining the short lifespan of blood cells (27).

HSCs were purified from mouse bone marrow using cell surface marker Thy-1low Lin (Lineage-markers)− Sca-1+ using multi-color fluorescence-activated cell sorting (FACS) and monoclonal antibodies (28, 29), with the representation of about 0.05% of C57BL/Ka-Thy-1.1 mouse bone marrow. Then, Morrison et al. showed that the Lin− population of cells included at least three multipotent populations: long-term HSCs, short-term HSCs, and multipotent progenitors (30). Subsequently, Boyer et al. established a lineage tracing mouse model that allowed for direct assessment of HSC differentiation pathways in vivo (31).

Using clonogenic B and T cell assays and in vitro erythroid potential assays, Lai and colleagues showed that different subsets of MPPs give rise to common lymphoid progenitors (CLP) and common myeloid progenitors (CMP). They demonstrated that lymphoid-committed CLPs do not emerge from the same MPP that gives rise to CMPs (32). Using in vivo differentiation, Adolfsson et al. have also shown that MPPs lose myeloid lineage differentiation potential during lymphoid lineage differentiation (33). Injection of lin−CD44+CD25−Sca-1+CD117c-kit+ (LSK), Flt3+ cells into lethally irradiated mice, demonstrated that LSK Flt3+ cells loose MegE differentiation potential before lymphoid lineage commitment, followed by a loss of GM differentiation potential (32).

Common lymphoid progenitors have two CLP subsets: CLP-1 (lin−Sca-1+CD117+/loCD127+CD135+) and CLP-2 (lin−Sca-1+CD117−CD127+CD135+B220+). Clonogenic assays demonstrated that CLP-2 are the most differentiated population with T cell potential before B cell commitment (34). These CLPs develop into immature early T-lineage progenitors (ETP), characterized as LSK with only low CD127 (IL-7Rα) expression, high T potential, and limited B potential. Using in vitro GFP tracing, Pui et al. showed that T lymphopoiesis is under the control of Notch signaling. Such ETPs then develop into immature T cells, which migrate to the thymus, where they mature (35).

Using flow cytometry, Loder et al. marked each step of B cell development from the CLP by unique gene expression patterns, as well as immunoglobulin H chain and L chain gene loci rearrangements. The rearrangements are in part due to the B cells undergoing V(D)J recombination (36). Bone marrow-derived immature B cells then migrate to the spleen. Using flow cytometry, Allman et al. showed that immature B cells pass through T1 and T2 transitional stages and finally differentiate to a T3 stage (37).

Using single-cell RT-PCR analysis, Hu et al. observed that both erythroid and myeloid gene expression programs are initiated by the same progenitor cells (MEPs) before exclusive commitment toward the myeloid or erythroid lineages (38). Although many of CD34+lin− primary bone marrow cells shared a specific phenotype, their gene expression varied, as ~50% of the cells expressed mRNA for both β-globin as seen with RBC differentiation and myeloperoxidase as seen with myeloid differentiation.

RECENT ADVANCES IN LINEAGE TRACING IN HEMATOPOIESIS

a) CyTOF and MALDI-TOF

While flow cytometry remains vital in HSC research, the technology to identify and quantify cells on a single-cell basis is continually improving.

CyTOF, or mass cytometry, is a quantitative alternative to flow cytometry. Instead of labeling antibodies with fluorochromes, CyTOF uses antibodies labeled with heavy metal ion tags, which are then analyzed by a mass spectroscopic readout (39). This technique allows for the simultaneous identification of multiple cell types from the same heterogeneous samples of blood.

To examine the interplay between normal human hematopoietic and immunological signaling in the human bone marrow, Bendall et al. recently used CyTOF to measure 34 cellular parameters simultaneously at a single-cell level. To analyze intracellular pathways as well as lineage-specific consequences of telomere erosion and the restoration of telomere length in rare HSPC populations, Raval et al. simultaneously measured 19 surface markers and 13 intracellular markers (40). To analyze how growth factors regulate human HSCs, Knapp et al. recently measured 43 different surface markers, transcription factors, active signaling molecules, viability, and cell-cycle signals in individual CD34+ cord blood-derived cells (41).

Matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) is now adapted to analyze protein contents in samples (42). Fuchs et al. used matrix-assisted laser desorption and ionization time-of-flight mass spectrometry under standard, nutrient-rich culture conditions, followed by low oxygen and low glucose concentrations to monitor changes in the composition and saturation degree of choline phospholipids of hematopoietic progenitor cells (43).

MALDI-TOF is used to elucidate glycosylation patterns, as well as to determine variations of different proteins. While Reinke et al. analyzed N-glycans of membrane proteins of hematopoietic cell lines to assess the various glycosylation patterns (44), Liu et al. identified the proteomic changes in myeloid dendritic cells in cases of severe aplastic anemia (45).

b) Single-cell RNA Sequencing

Single-cell RNA sequencing (scRNA-seq) is a robust method to investigate cell-to-cell variation at the transcriptome level in hematopoiesis (46). Using scRNA-seq, cell purification and functional clonal assays have revised the model of hematopoietic development, especially for the T, B, and NK lineages.

Recent single cell studies suggest that oligopotent progenitors contain only a small portion of the hematopoietic hierarchy. Instead, multipotent cells differentiate into unipotent cells of the myeloid (My)- erythroid (Er)- megakaryocyte (Mk) lineages, which suggests two tiers of the human blood hierarchy: one with multipotent cells, and another with cells committed to My, Er, or Mk lineages. However, Mk branching differs in fetal liver and bone marrow. While in the fetal liver, Mk progenitors are enriched, but not restricted, to the stem cell compartment. However, in the bone marrow, Mk fate is coupled to multipotent cells. This result corraborates the two-tier model of adult hematopoiesis, where branching of Mk occurs at the level of HSC/MPPs.

To examine the molecular basis for the two-tier hierarchy, Dick et al. have performed low cell-input RNA sequencing, enhanced reduced representation bisulfite sequencing, and ATAC-seq to provide a comprehensive transcriptional and epigenetic roadmap of human HSPCs across development. Additionally, Nestorowa et al. used single-cell RNA sequencing to profile more than 1600 single HSPCs to reconstruct differentiation trajectories and dynamic expression changes associated with early lymphoid, erythroid, and granulocyte-macrophage differentiation (47).

c) CRISPR/Cas9-based Genome Editing

The CRISPR/Cas9-based, genome editing system, targets specific sequences in the genome for the generation of mouse lines with point mutations, deletions, conditional deletions, or reporter expression (48). It has extensively been used to knockout hematopoietic genes and the β-globin gene in human HSCs (49). Since the CRISPR/Cas9 system can be multiplexed for manipulations of multiple genes at once (50), it allows for multiple genetic modifications in a single mouse line for the investigation of multiple hematopoietic genes within the same organism (51).

d) Polylox Barcoding

Polylox barcoding is a recombinase-based approach that enables fate mapping in the hematopoietic system under physiological conditions (52). The Polylox locus consists of an array of unique DNA sequences interspersed with loxP sites. Barcodes get created in vivo through Cre-dependent recombination (52).

The Polylox system shares some features with the CRISPR/Cas9-based lineage-tracing approaches, allowing the barcode generation in vivo (52). However, in the Polylox system, each of the individual DNA blocks is about 170 base pairs long, and it is necessary to sequence across the whole locus to obtain the full barcode information (52). Therefore, CRISPR–Cas9-based systems where barcodes can differ by just single nucleotides may be more prone to PCR and sequencing artifacts than the Polylox system.

To study the origin and clonal composition of HSCs in the adult bone marrow after embryonic barcode induction, Pei et al. recently treated embryos containing the Polylox locus at E9.5 by administering the mother a single dose of tamoxifen. They then could determine the barcodes of sorted single HSCs (52). Such high-resolution fate mapping by Polylox barcoding of embryonic HSC progenitors and adult HSCs supports a bifurcating tree model of hematopoiesis, which was proposed in the 1980s (53) but has not yet been tested under physiological conditions yet.

e) Multiplexed Fluorescent Labeling and Sequencing

Heterogeneity among cells within tissues is recognized in both normal and malignant blood development (46, 54) (55, 56). The hematopoietic system contains populations of cells with divergent properties and distinctive behaviors, such as cell production and lineage bias (57, 58). HSCs exhibit a bias toward myeloid, lymphoid, or megakaryocytic lineage upon transplantation of single cells (57, 59, 60) with ex vivo barcoding, transplantation of populations of cells (55, 61–67), or by retrotransposon tagging of endogenous cells (68).

The single-cell transplant data are coupled with single-cell gene expression analysis on different cells to resolve subpopulations with corresponding gene expression and repopulation potential (69). Overlaying in vivo functional behavior of endogenous HSC clones with their gene expression and epigenetic characteristics has coupled the function of gene expression and chromatin state at the clonal resolution and established the cell-autonomous epigenetic constraints bound the HSC function.

f) Tissue Engineering and 3D Scaffold Development

The fate and development of HSCs is dependent on their tissue microenvironment during fetal and adult development, such as AGM, fetal liver, and bone marrow. Therefore, it is prudent to recreate a 3D microenvironment using biomaterials-based 3D bioprinted scaffold.

Wagner et al. demonstrated that the self-renewal capacity of HSCs was higher in 2D co-culture with bone-marrow-derived adherent cells (70). Then, Taqvi et al. and Ferreiera et al. used biocompatible materials to culture umbilical cord blood-derived CD34+ HSPCs on constructs with a variety of pore size and topology (70, 71). Recently, microfluidics-based organ-on-a-chip approach has been utilized to investigate the roles of wall shear stress of hematopoietic development (73).

To accurately mimic tissue architecture and components, we yet to analyze the composition of scaffolding proteins, matrix-bound soluble factors, 3D structure, topography, nanoroughness, stiffness, and biophysical properties of hematopoietic tissue microenvironment. Given the recent advances in tissue engineering and 3D bioprinting, we are hopeful that 3D bioprinted AGM, fetal liver, and bone marrow will be developed for HSC formation, expansion, and development.

CONCLUSION

Lineage tracing has established a family tree of hematopoiesis from the mesoderm to adult hematopoietic lineages. While recent advances in quantitative approaches to cell fate mapping have found clonality of HSCs, it is unclear when and where HSCs become lineage-biased during their development. We have illustrated how classical and state-of-the-art methods have resolved the hierarchy in hematopoiesis.

TABLE 1.

Lineage tracing methods in the study of hematopoiesis.

Approach Utility in hematopoietic development
Mass Cytometry (CyTOF) Allows for simultaneous identification of multiple cell types from heterogeneous sample of blood
Matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) Analyzes protein contents in samples and elucidates glycosylation patterns
Single-cell RNA Sequencing Investigates cell-to-cell variation at transcription level
CRISPR/Cas9-based Genome Editing Used to knock out hematopoietic genes and the β-globin gene in human HSCs and allows for multiple genetic modifications
Polylox Barcoding To study origin and clonal composition of HSCs
Multiplexed Fluorescent Labeling and Sequencing The single-cell transplant data are coupled with single-cell gene expression analysis on different cells to resolve subpopulations with corresponding gene expression and repopulation potential
Tissue Engineering & 3D Scaffold Development Recreates 3D microenvironment conducive for HSC formation, expansion, development, and differentiation.
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Acknowledgments

DIS is supported by grants from the National Heart, Lung, and Blood Institute (HL131645) and St. Baldrick Foundation (St. Baldrick Scholar Award).

Footnotes

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References

  • 1.Orkin SH, Zon LI. Hematopoiesis: an evolving paradigm for stem cell biology. Cell. 2008;132(4):631–44. doi: 10.1016/j.cell.2008.01.025. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 2.McGrath KE, Frame JM, Fromm GJ, Koniski AD, Kingsley PD, Little J, Bulger M, Palis J. A transient definitive erythroid lineage with unique regulation of the beta-globin locus in the mammalian embryo. Blood. 2011;117(17):4600–8. doi: 10.1182/blood-2010-12-325357. Epub 2011/03/08. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 3.Kretzschmar K, Watt FM. Lineage tracing. Cell. 2012;148(1–2):33–45. doi: 10.1016/j.cell.2012.01.002. Epub 2012/01/24. [DOI] [PubMed] [Google Scholar]
  • 4.Martin C, Beaupain D, Dieterlen-Lievre F. Developmental relationships between vitelline and intra-embryonic haemopoiesis studied in avian ‘yolk sac chimaeras’. Cell Differ. 1978;7(3):115–30. doi: 10.1016/0045-6039(78)90012-x. Epub 1978/06/01. [DOI] [PubMed] [Google Scholar]
  • 5.Swiers G, de Bruijn M, Speck NA. Hematopoietic stem cell emergence in the conceptus and the role of Runx1. Int J Dev Biol. 2010;54(6–7):1151–63. doi: 10.1387/ijdb.103106gs. Epub 2010/08/17. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 6.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(22):5073–84. doi: 10.1242/dev.126.22.5073. Epub 1999/10/26. [DOI] [PubMed] [Google Scholar]
  • 7.Inman KE, Downs KM. The murine allantois: emerging paradigms in development of the mammalian umbilical cord and its relation to the fetus. Genesis. 2007;45(5):237–58. doi: 10.1002/dvg.20281. Epub 2007/04/19. [DOI] [PubMed] [Google Scholar]
  • 8.Gekas C, Dieterlen-Lievre F, Orkin SH, Mikkola HK. The placenta is a niche for hematopoietic stem cells. Dev Cell. 2005;8(3):365–75. doi: 10.1016/j.devcel.2004.12.016. Epub 2005/03/02. [DOI] [PubMed] [Google Scholar]
  • 9.Ottersbach K, Dzierzak E. The murine placenta contains hematopoietic stem cells within the vascular labyrinth region. Dev Cell. 2005;8(3):377–87. doi: 10.1016/j.devcel.2005.02.001. Epub 2005/03/02. [DOI] [PubMed] [Google Scholar]
  • 10.Tam PP, Behringer RR. Mouse gastrulation: the formation of a mammalian body plan. Mech Dev. 1997;68(1–2):3–25. doi: 10.1016/s0925-4773(97)00123-8. Epub 1998/02/12. [DOI] [PubMed] [Google Scholar]
  • 11.Garcia-Martinez V, Schoenwolf GC. Primitive-streak origin of the cardiovascular system in avian embryos. Dev Biol. 1993;159(2):706–19. doi: 10.1006/dbio.1993.1276. Epub 1993/10/01. [DOI] [PubMed] [Google Scholar]
  • 12.Xiong JW. Molecular and developmental biology of the hemangioblast. Dev Dyn. 2008;237(5):1218–31. doi: 10.1002/dvdy.21542. Epub 2008/04/23. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 13.Padron-Barthe L, Temino S, Villa del Campo C, Carramolino L, Isern J, Torres M. Clonal analysis identifies hemogenic endothelium as the source of the blood-endothelial common lineage in the mouse embryo. Blood. 2014;124(16):2523–32. doi: 10.1182/blood-2013-12-545939. Epub 2014/08/21. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 14.Lancrin C, Sroczynska P, Stephenson C, Allen T, Kouskoff V, Lacaud G. The haemangioblast generates haematopoietic cells through a haemogenic endothelium stage. Nature. 2009;457(7231):892–5. doi: 10.1038/nature07679. Epub 2009/02/03. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 15.Vogeli KM, Jin SW, Martin GR, Stainier DY. A common progenitor for haematopoietic and endothelial lineages in the zebrafish gastrula. Nature. 2006;443(7109):337–9. doi: 10.1038/nature05045. Epub 2006/09/22. [DOI] [PubMed] [Google Scholar]
  • 16.North T, Gu TL, Stacy T, Wang Q, Howard L, Binder M, Marin-Padilla M, Speck NA. Cbfa2 is required for the formation of intra-aortic hematopoietic clusters. Development. 1999;126(11):2563–75. doi: 10.1242/dev.126.11.2563. Epub 1999/05/05. [DOI] [PubMed] [Google Scholar]
  • 17.North TE, Stacy T, Matheny CJ, Speck NA, de Bruijn MF. Runx1 is expressed in adult mouse hematopoietic stem cells and differentiating myeloid and lymphoid cells, but not in maturing erythroid cells. Stem Cells. 2004;22(2):158–68. doi: 10.1634/stemcells.22-2-158. Epub 2004/03/03. [DOI] [PubMed] [Google Scholar]
  • 18.Godin I, Dieterlen-Lievre F, Cumano A. Emergence of multipotent hemopoietic cells in the yolk sac and paraaortic splanchnopleura in mouse embryos, beginning at 8.5 days postcoitus. Proc Natl Acad Sci U S A. 1995;92(3):773–7. doi: 10.1073/pnas.92.3.773. Epub 1995/01/31. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 19.Medvinsky A, Dzierzak E. Definitive hematopoiesis is autonomously initiated by the AGM region. Cell. 1996;86(6):897–906. doi: 10.1016/s0092-8674(00)80165-8. Epub 1996/09/20. [DOI] [PubMed] [Google Scholar]
  • 20.Zovein AC, Hofmann JJ, Lynch M, French WJ, Turlo KA, Yang Y, Becker MS, Zanetta L, Dejana E, Gasson JC, Tallquist MD, Iruela-Arispe ML. Fate tracing reveals the endothelial origin of hematopoietic stem cells. Cell Stem Cell. 2008;3(6):625–36. doi: 10.1016/j.stem.2008.09.018. Epub 2008/12/02. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 21.Bertrand JY, Chi NC, Santoso B, Teng S, Stainier DY, Traver D. Haematopoietic stem cells derive directly from aortic endothelium during development. Nature. 2010;464(7285):108–11. doi: 10.1038/nature08738. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • **22.Anderson H, Patch TC, Reddy PN, Hagedorn EJ, Kim PG, Soltis KA, Chen MJ, Tamplin OJ, Frye M, MacLean GA, Hubner K, Bauer DE, Kanki JP, Vogin G, Huston NC, Nguyen M, Fujiwara Y, Paw BH, Vestweber D, Zon LI, Orkin SH, Daley GQ, Shah DI. Hematopoietic stem cells develop in the absence of endothelial cadherin 5 expression. Blood. 2015 doi: 10.1182/blood-2015-07-659276. This seminal article is first to demonstratre the utility of zebrafish parabiotic fusion method in tracking origin, development, and differentiation of hematopoietic stem cells. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 23.Eilken HM, Nishikawa S, Schroeder T. Continuous single-cell imaging of blood generation from haemogenic endothelium. Nature. 2009;457(7231):896–900. doi: 10.1038/nature07760. Epub 2009/02/13. [DOI] [PubMed] [Google Scholar]
  • 24.de Bruijn MF, Speck NA, Peeters MC, Dzierzak E. Definitive hematopoietic stem cells first develop within the major arterial regions of the mouse embryo. EMBO J. 2000;19(11):2465–74. doi: 10.1093/emboj/19.11.2465. Epub 2000/06/03. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 25.Chen MJ, Li Y, De Obaldia ME, Yang Q, Yzaguirre AD, Yamada-Inagawa T, Vink CS, Bhandoola A, Dzierzak E, Speck NA. Erythroid/myeloid progenitors and hematopoietic stem cells originate from distinct populations of endothelial cells. Cell stem cell. 2011;9(6):541–52. doi: 10.1016/j.stem.2011.10.003. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 26.Cai Z, de Bruijn M, Ma X, Dortland B, Luteijn T, Downing RJ, Dzierzak E. Haploinsufficiency of AML1 affects the temporal and spatial generation of hematopoietic stem cells in the mouse embryo. Immunity. 2000;13(4):423–31. doi: 10.1016/s1074-7613(00)00042-x. Epub 2000/11/09. [DOI] [PubMed] [Google Scholar]
  • 27.van Galen P, Kreso A, Mbong N, Kent DG, Fitzmaurice T, Chambers JE, Xie S, Laurenti E, Hermans K, Eppert K, Marciniak SJ, Goodall JC, Green AR, Wouters BG, Wienholds E, Dick JE. The unfolded protein response governs integrity of the haematopoietic stem-cell pool during stress. Nature. 2014;510(7504):268–72. doi: 10.1038/nature13228. Epub 2014/04/30. [DOI] [PubMed] [Google Scholar]
  • 28.Muller-Sieburg CE, Whitlock CA, Weissman IL. Isolation of two early B lymphocyte progenitors from mouse marrow: a committed pre-pre-B cell and a clonogenic Thy-1-lo hematopoietic stem cell. Cell. 1986;44(4):653–62. doi: 10.1016/0092-8674(86)90274-6. Epub 1986/02/28. [DOI] [PubMed] [Google Scholar]
  • 29.Spangrude GJ, Aihara Y, Weissman IL, Klein J. The stem cell antigens Sca-1 and Sca-2 subdivide thymic and peripheral T lymphocytes into unique subsets. J Immunol. 1988;141(11):3697–707. Epub 1988/12/01. [PubMed] [Google Scholar]
  • 30.Morrison SJ, Weissman IL. The long-term repopulating subset of hematopoietic stem cells is deterministic and isolatable by phenotype. Immunity. 1994;1(8):661–73. doi: 10.1016/1074-7613(94)90037-x. Epub 1994/11/01. [DOI] [PubMed] [Google Scholar]
  • 31.Boyer SW, Schroeder AV, Smith-Berdan S, Forsberg EC. All hematopoietic cells develop from hematopoietic stem cells through Flk2/Flt3-positive progenitor cells. Cell Stem Cell. 2011;9(1):64–73. doi: 10.1016/j.stem.2011.04.021. Epub 2011/07/06. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 32.Lai AY, Kondo M. T and B lymphocyte differentiation from hematopoietic stem cell. Semin Immunol. 2008;20(4):207–12. doi: 10.1016/j.smim.2008.05.002. Epub 2008/06/28. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 33.Adolfsson J, Mansson R, Buza-Vidas N, Hultquist A, Liuba K, Jensen CT, Bryder D, Yang L, Borge OJ, Thoren LA, Anderson K, Sitnicka E, Sasaki Y, Sigvardsson M, Jacobsen SE. Identification of Flt3+ lympho-myeloid stem cells lacking erythro-megakaryocytic potential a revised road map for adult blood lineage commitment. Cell. 2005;121(2):295–306. doi: 10.1016/j.cell.2005.02.013. Epub 2005/04/27. [DOI] [PubMed] [Google Scholar]
  • 34.Martin CH, Aifantis I, Scimone ML, von Andrian UH, Reizis B, von Boehmer H, Gounari F. Efficient thymic immigration of B220+ lymphoid-restricted bone marrow cells with T precursor potential. Nat Immunol. 2003;4(9):866–73. doi: 10.1038/ni965. Epub 2003/08/20. [DOI] [PubMed] [Google Scholar]
  • 35.Pui JC, Allman D, Xu L, DeRocco S, Karnell FG, Bakkour S, Lee JY, Kadesch T, Hardy RR, Aster JC, Pear WS. Notch1 expression in early lymphopoiesis influences B versus T lineage determination. Immunity. 1999;11(3):299–308. doi: 10.1016/s1074-7613(00)80105-3. Epub 1999/10/08. [DOI] [PubMed] [Google Scholar]
  • 36.Loder F, Mutschler B, Ray RJ, Paige CJ, Sideras P, Torres R, Lamers MC, Carsetti R. B cell development in the spleen takes place in discrete steps and is determined by the quality of B cell receptor-derived signals. J Exp Med. 1999;190(1):75–89. doi: 10.1084/jem.190.1.75. Epub 1999/08/03. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 37.Allman D, Lindsley RC, DeMuth W, Rudd K, Shinton SA, Hardy RR. Resolution of three nonproliferative immature splenic B cell subsets reveals multiple selection points during peripheral B cell maturation. J Immunol. 2001;167(12):6834–40. doi: 10.4049/jimmunol.167.12.6834. Epub 2001/12/12. [DOI] [PubMed] [Google Scholar]
  • 38.Hu M, Krause D, Greaves M, Sharkis S, Dexter M, Heyworth C, Enver T. Multilineage gene expression precedes commitment in the hemopoietic system. Genes Dev. 1997;11(6):774–85. doi: 10.1101/gad.11.6.774. Epub 1997/03/15. [DOI] [PubMed] [Google Scholar]
  • 39.Bandura DR, Baranov VI, Ornatsky OI, Antonov A, Kinach R, Lou X, Pavlov S, Vorobiev S, Dick JE, Tanner SD. Mass cytometry: technique for real time single cell multitarget immunoassay based on inductively coupled plasma time-of-flight mass spectrometry. Anal Chem. 2009;81(16):6813–22. doi: 10.1021/ac901049w. Epub 2009/07/16. [DOI] [PubMed] [Google Scholar]
  • 40.Raval A, Behbehani GK, Nguyen le XT, Thomas D, Kusler B, Garbuzov A, Ramunas J, Holbrook C, Park CY, Blau H, Nolan GP, Artandi SE, Mitchell BS. Reversibility of Defective Hematopoiesis Caused by Telomere Shortening in Telomerase Knockout Mice. PLoS One. 2015;10(7):e0131722. doi: 10.1371/journal.pone.0131722. Epub 2015/07/03. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • *41.Knapp DJ, Hammond CA, Aghaeepour N, Miller PH, Pellacani D, Beer PA, Sachs K, Qiao W, Wang W, Humphries RK, Sauvageau G, Zandstra PW, Bendall SC, Nolan GP, Hansen C, Eaves CJ. Distinct signaling programs control human hematopoietic stem cell survival and proliferation. Blood. 2017;129(3):307–18. doi: 10.1182/blood-2016-09-740654. Epub 2016/11/10. Using CyTOF method, this article demonstrates that human HSCs have higher tonic signaling activity in multiple pathways than MPPs. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 42.Clark AE, Kaleta EJ, Arora A, Wolk DM. Matrix-assisted laser desorption ionization-time of flight mass spectrometry: a fundamental shift in the routine practice of clinical microbiology. Clin Microbiol Rev. 2013;26(3):547–603. doi: 10.1128/CMR.00072-12. Epub 2013/07/05. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 43.Fuchs B, Schnapka-Hille L, Schiller J, Cross MA. Oxygen and cytokine-dependent changes in choline phospholipid saturation in hematopoietic progenitor cells detected by MALDI-TOF mass spectrometry. Chem Phys Lipids. 2011;164(7):636–42. doi: 10.1016/j.chemphyslip.2011.06.003. Epub 2011/07/05. [DOI] [PubMed] [Google Scholar]
  • 44.Reinke SO, Bayer M, Berger M, Hinderlich S, Blanchard V. The analysis of N-glycans of cell membrane proteins from human hematopoietic cell lines reveals distinctions in their pattern. Biol Chem. 2012;393(8):731–47. doi: 10.1515/hsz-2012-0195. Epub 2012/09/05. [DOI] [PubMed] [Google Scholar]
  • 45.Liu C, Sheng W, Fu R, Wang H, Li L, Liu H, Shao Z. Differential expression of the proteome of myeloid dendritic cells in severe aplastic anemia. Cell Immunol. 2013;285(1–2):141–8. doi: 10.1016/j.cellimm.2013.09.007. Epub 2013/11/05. [DOI] [PubMed] [Google Scholar]
  • 46.Rostom R, Svensson V, Teichmann SA, Kar G. Computational approaches for interpreting scRNA-seq data. FEBS Lett. 2017;591(15):2213–25. doi: 10.1002/1873-3468.12684. Epub 2017/05/20. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 47.Nestorowa S, Hamey FK, Pijuan Sala B, Diamanti E, Shepherd M, Laurenti E, Wilson NK, Kent DG, Gottgens B. A single-cell resolution map of mouse hematopoietic stem and progenitor cell differentiation. Blood. 2016;128(8):e20–31. doi: 10.1182/blood-2016-05-716480. Epub 2016/07/02. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 48.Yang H, Wang H, Shivalila CS, Cheng AW, Shi L, Jaenisch R. One-step generation of mice carrying reporter and conditional alleles by CRISPR/Cas-mediated genome engineering. Cell. 2013;154(6):1370–9. doi: 10.1016/j.cell.2013.08.022. Epub 2013/09/03. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • **49.Dever DP, Bak RO, Reinisch A, Camarena J, Washington G, Nicolas CE, Pavel-Dinu M, Saxena N, Wilkens AB, Mantri S, Uchida N, Hendel A, Narla A, Majeti R, Weinberg KI, Porteus MH. CRISPR/Cas9 beta-globin gene targeting in human haematopoietic stem cells. Nature. 2016;539(7629):384–9. doi: 10.1038/nature20134. Epub 2016/11/08. This article has used CRISPR-based methodology for targeting hematopoietic stem cells by homologous recombination at the β-globin locus to advance the development of next-generation therapies for β-haemoglobinopathies. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 50.Cong L, Ran FA, Cox D, Lin S, Barretto R, Habib N, Hsu PD, Wu X, Jiang W, Marraffini LA, Zhang F. Multiplex genome engineering using CRISPR/Cas systems. Science. 2013;339(6121):819–23. doi: 10.1126/science.1231143. Epub 2013/01/05. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 51.Schmitt CE, Lizama CO, Zovein AC. From transplantation to transgenics: mouse models of developmental hematopoiesis. Experimental hematology. 2014;42(8):707–16. doi: 10.1016/j.exphem.2014.06.008. [DOI] [PubMed] [Google Scholar]
  • **52.Pei W, Feyerabend TB, Rossler J, Wang X, Postrach D, Busch K, Rode I, Klapproth K, Dietlein N, Quedenau C, Chen W, Sauer S, Wolf S, Hofer T, Rodewald HR. Polylox barcoding reveals haematopoietic stem cell fates realized in vivo. Nature. 2017;548(7668):456–60. doi: 10.1038/nature23653. Epub 2017/08/17. Using polylox technology, this seminal article has demonstrated a basic split between common myeloid-erythroid development and common lymphocyte development, supporting the long-held but contested view of a tree-like hematopoietic structure. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 53.Dick JE, Magli MC, Huszar D, Phillips RA, Bernstein A. Introduction of a selectable gene into primitive stem cells capable of long-term reconstitution of the hemopoietic system of W/Wv mice. Cell. 1985;42(1):71–9. doi: 10.1016/s0092-8674(85)80102-1. Epub 1985/08/01. [DOI] [PubMed] [Google Scholar]
  • 54.Ding L, Ley TJ, Larson DE, Miller CA, Koboldt DC, Welch JS, Ritchey JK, Young MA, Lamprecht T, McLellan MD, McMichael JF, Wallis JW, Lu C, Shen D, Harris CC, Dooling DJ, Fulton RS, Fulton LL, Chen K, Schmidt H, Kalicki-Veizer J, Magrini VJ, Cook L, McGrath SD, Vickery TL, Wendl MC, Heath S, Watson MA, Link DC, Tomasson MH, Shannon WD, Payton JE, Kulkarni S, Westervelt P, Walter MJ, Graubert TA, Mardis ER, Wilson RK, DiPersio JF. Clonal evolution in relapsed acute myeloid leukaemia revealed by whole-genome sequencing. Nature. 2012;481(7382):506–10. doi: 10.1038/nature10738. Epub 2012/01/13. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 55.Lemischka IR, Raulet DH, Mulligan RC. Developmental potential and dynamic behavior of hematopoietic stem cells. Cell. 1986;45(6):917–27. doi: 10.1016/0092-8674(86)90566-0. Epub 1986/06/20. [DOI] [PubMed] [Google Scholar]
  • 56.Notta F, Doulatov S, Laurenti E, Poeppl A, Jurisica I, Dick JE. Isolation of single human hematopoietic stem cells capable of long-term multilineage engraftment. Science. 2011;333(6039):218–21. doi: 10.1126/science.1201219. Epub 2011/07/09. [DOI] [PubMed] [Google Scholar]
  • 57.Dykstra B, Kent D, Bowie M, McCaffrey L, Hamilton M, Lyons K, Lee SJ, Brinkman R, Eaves C. Long-term propagation of distinct hematopoietic differentiation programs in vivo. Cell Stem Cell. 2007;1(2):218–29. doi: 10.1016/j.stem.2007.05.015. Epub 2008/03/29. [DOI] [PubMed] [Google Scholar]
  • 58.Picelli S, Bjorklund AK, Faridani OR, Sagasser S, Winberg G, Sandberg R. Smart-seq2 for sensitive full-length transcriptome profiling in single cells. Nat Methods. 2013;10(11):1096–8. doi: 10.1038/nmeth.2639. Epub 2013/09/24. [DOI] [PubMed] [Google Scholar]
  • 59.Dykstra B, Olthof S, Schreuder J, Ritsema M, de Haan G. Clonal analysis reveals multiple functional defects of aged murine hematopoietic stem cells. J Exp Med. 2011;208(13):2691–703. doi: 10.1084/jem.20111490. Epub 2011/11/24. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 60.Morita Y, Ema H, Nakauchi H. Heterogeneity and hierarchy within the most primitive hematopoietic stem cell compartment. J Exp Med. 2010;207(6):1173–82. doi: 10.1084/jem.20091318. Epub 2010/04/28. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 61.Aiuti A, Biasco L, Scaramuzza S, Ferrua F, Cicalese MP, Baricordi C, Dionisio F, Calabria A, Giannelli S, Castiello MC, Bosticardo M, Evangelio C, Assanelli A, Casiraghi M, Di Nunzio S, Callegaro L, Benati C, Rizzardi P, Pellin D, Di Serio C, Schmidt M, Von Kalle C, Gardner J, Mehta N, Neduva V, Dow DJ, Galy A, Miniero R, Finocchi A, Metin A, Banerjee PP, Orange JS, Galimberti S, Valsecchi MG, Biffi A, Montini E, Villa A, Ciceri F, Roncarolo MG, Naldini L. Lentiviral hematopoietic stem cell gene therapy in patients with Wiskott-Aldrich syndrome. Science. 2013;341(6148):1233151. doi: 10.1126/science.1233151. Epub 2013/07/13. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 62.Gerrits A, Dykstra B, Kalmykowa OJ, Klauke K, Verovskaya E, Broekhuis MJ, de Haan G, Bystrykh LV. Cellular barcoding tool for clonal analysis in the hematopoietic system. Blood. 2010;115(13):2610–8. doi: 10.1182/blood-2009-06-229757. Epub 2010/01/23. [DOI] [PubMed] [Google Scholar]
  • 63.Jordan CT, Lemischka IR. Clonal and systemic analysis of long-term hematopoiesis in the mouse. Genes Dev. 1990;4(2):220–32. doi: 10.1101/gad.4.2.220. Epub 1990/02/01. [DOI] [PubMed] [Google Scholar]
  • 64.Lu R, Neff NF, Quake SR, Weissman IL. Tracking single hematopoietic stem cells in vivo using high-throughput sequencing in conjunction with viral genetic barcoding. Nat Biotechnol. 2011;29(10):928–33. doi: 10.1038/nbt.1977. Epub 2011/10/04. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 65.Mazurier S, Lemunier M, Siblot S, Mougel C, Lemanceau P. Distribution and diversity of type III secretion system-like genes in saprophytic and phytopathogenic fluorescent pseudomonads. FEMS Microbiol Ecol. 2004;49(3):455–67. doi: 10.1016/j.femsec.2004.04.019. Epub 2004/09/01. [DOI] [PubMed] [Google Scholar]
  • **66.Yu VW, Yusuf RZ, Oki T, Wu J, Saez B, Wang X, Cook C, Baryawno N, Ziller MJ, Lee E, Gu H, Meissner A, Lin CP, Kharchenko PV, Scadden DT. Epigenetic Memory Underlies Cell-Autonomous Heterogeneous Behavior of Hematopoietic Stem Cells. Cell. 2017;168(5):944–5. doi: 10.1016/j.cell.2017.02.010. Epub 2017/02/25. This seminal article demonstrates that intra-clonal behaviors HSC correspond to epigenetic configuration but not always to transcriptional state. Therefore, hematopoiesis under homeostatic and stress conditions represents the integrated action of highly heterogeneous clones of HSC with epigenetically scripted behaviors. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 67.Snodgrass R, Keller G. Clonal fluctuation within the haematopoietic system of mice reconstituted with retrovirus-infected stem cells. EMBO J. 1987;6(13):3955–60. doi: 10.1002/j.1460-2075.1987.tb02737.x. Epub 1987/12/20. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 68.Evrony GD, Lee E, Mehta BK, Benjamini Y, Johnson RM, Cai X, Yang L, Haseley P, Lehmann HS, Park PJ, Walsh CA. Cell lineage analysis in human brain using endogenous retroelements. Neuron. 2015;85(1):49–59. doi: 10.1016/j.neuron.2014.12.028. Epub 2015/01/09. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • *69.Wilson NK, Kent DG, Buettner F, Shehata M, Macaulay IC, Calero-Nieto FJ, Sanchez Castillo M, Oedekoven CA, Diamanti E, Schulte R, Ponting CP, Voet T, Caldas C, Stingl J, Green AR, Theis FJ, Gottgens B. Combined Single-Cell Functional and Gene Expression Analysis Resolves Heterogeneity within Stem Cell Populations. Cell Stem Cell. 2015;16(6):712–24. doi: 10.1016/j.stem.2015.04.004. Epub 2015/05/26. This article has combined single-cell HSC transplantation assays with flow cytometric index sorting and single-cell gene expression assays. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 70.Wagner W, Wein F, Roderburg C, Saffrich R, Faber A, Krause U, Schubert M, Benes V, Eckstein V, Maul H, Ho AD. Adhesion of hematopoietic progenitor cells to human mesenchymal stem cells as a model for cell-cell interaction. Exp Hematol. 2007;35(2):314–325. doi: 10.1016/j.exphem.2006.10.003. [DOI] [PubMed] [Google Scholar]
  • 71.Taqvi S, Dixit L, Roy K. Biomaterial-based notch signaling for the differentiation of hematopoietic stem cells into T cells. J Biomed Mater Res Part A. 2006;79:689–697. doi: 10.1002/jbm.a.30916. [DOI] [PubMed] [Google Scholar]
  • 72.Ferreira MS, Jahnen-Dechent W, Labude N, Bovi M, et al. Cord blood-hematopoietic stem cell expansion in 3D fibrin scaffolds with stromal support. Biomaterials. 2012;33:6987–6997. doi: 10.1016/j.biomaterials.2012.06.029. [DOI] [PubMed] [Google Scholar]
  • 73.Diaz MF, Li N, Lee HJ, Adamo L, Evans SM, Willey HE, Arora N, Torisawa YS, Vickers DA, Morris SA, Naveiras O, Murthy SK, Ingber DE, Daley GQ, García-Cardeña G, Wenzel PL. Biomechanical forces promote blood development through prostaglandin E2 and the cAMP-PKA signaling axis. J Exp Med. 2015;212(5):665–80. doi: 10.1084/jem.20142235. [DOI] [PMC free article] [PubMed] [Google Scholar]

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