• Article |

    The single-cell transcriptional profile of a human embryo between 16 and 19 days after fertilization reveals parallels and differences in gastrulation in humans as compared with mouse and non-human primate models.

    • Richard C. V. Tyser
    • , Elmir Mahammadov
    •  & Shankar Srinivas
  • Article |

    A single-cell atlas of human fetal bone marrow in healthy fetuses and fetuses with Down syndrome provides insight into developmental haematopoiesis in humans and the transcription and functional differences that occur in Down syndrome.

    • Laura Jardine
    • , Simone Webb
    •  & Muzlifah Haniffa
  • Article |

    Whole-genome sequencing of haematopoietic colonies from human fetuses reveals the somatic mutations acquired by individual progenitors, which are used as barcodes to construct a phylogenetic tree of blood development.

    • Michael Spencer Chapman
    • , Anna Maria Ranzoni
    •  & Ana Cvejic
  • Article |

    A combination of fluorescent antibodies is used to build visual maps of all myeloid cells in the bone marrow, providing new insight into how the bone marrow microenvironment regulates cell-fate decisions.

    • Jizhou Zhang
    • , Qingqing Wu
    •  & Daniel Lucas
  • Article |

    MLLT3 is identified as a crucial regulator of the self-renewal of human haematopoietic stem cells, and helps to maintain an active chromatin state in haematopoietic stem-cell regulatory genes during culture.

    • Vincenzo Calvanese
    • , Andrew T. Nguyen
    •  & Hanna K. A. Mikkola
  • Article |

    Single-cell transcriptomic profiling of fetal liver, skin, kidney and yolk sac reveals the differentiation trajectories of human haematopoietic stem cells and multipotent progenitors, which are validated to produce an integrated map of fetal liver haematopoiesis.

    • Dorin-Mirel Popescu
    • , Rachel A. Botting
    •  & Muzlifah Haniffa
  • Article |

    The transcriptional landscape of cell populations of the mouse bone marrow microenvironment, mapped at single-cell resolution, reveals cellular heterogeneity in this niche as well as substantial transcriptional remodelling under stress conditions.

    • Anastasia N. Tikhonova
    • , Igor Dolgalev
    •  & Iannis Aifantis
  • Article |

    Analysis of blood from a healthy human show that haematopoietic stem cells increase rapidly in numbers through early life, reaching a stable plateau in adulthood, and contribute to myeloid and B lymphocyte populations throughout life.

    • Henry Lee-Six
    • , Nina Friesgaard Øbro
    •  & Peter J. Campbell
  • Letter |

    The production of haematopoietic stem cells is repressed during early mammalian embryogenesis by an epigenetic mechanism that involves the action of the Polycomb protein EZH1.

    • Linda T. Vo
    • , Melissa A. Kinney
    •  & George Q. Daley
  • Letter |

    Transposon tagging to clonally trace progenitors and stem cells provides evidence for a substantially revised roadmap for unperturbed haematopoiesis, and highlights unique properties of multipotent progenitors and haematopoietic stem cells in situ.

    • Alejo E. Rodriguez-Fraticelli
    • , Samuel L. Wolock
    •  & Fernando D. Camargo
  • Letter |

    An in vivo imaging-based competitive transplant screen in zebrafish identifies epoxyeicosatrienoic acids as enhancers of haematopoietic stem and progenitor cell (HSPC) engraftment; these derivatives of arachidonic acid also promote zebrafish developmental HSPC specification through a PI(3)K-dependent AP-1 and runx1 transcriptional program and their pro-engraftment effect is conserved in mammals (indicating clinical potential).

    • Pulin Li
    • , Jamie L. Lahvic
    •  & Leonard I. Zon
  • Article |

    On the basis of transplantation experiments it is generally believed that a very small number of haematopoietic stem cells maintain multi-lineage haematopoiesis by stably producing a hierarchy of short-lived progenitor cells; here a new transposon-based labelling technique shows that this might not be the case during non-transplant haematopoiesis, but rather that a large number of long-lived progenitors are the main drivers of steady-state haematopoiesis during most of adulthood.

    • Jianlong Sun
    • , Azucena Ramos
    •  & Fernando D. Camargo
  • Letter |

    Under stress conditions such as acute blood loss or chronic anaemia, glucocorticoids trigger self-renewal of early burst-forming unit–erythroid (BFU–E) progenitors in the spleen, however, the mechanism of glucocorticoid action is not well understood; here the RNA binding protein ZFP36L2 is identified as a transcriptional target of the glucocorticoid receptor in BFU-Es and is shown to be involved in the process of erythroid cell expansion following exposure to glucocorticoids.

    • Lingbo Zhang
    • , Lina Prak
    •  & Harvey F. Lodish
  • Letter |

    In vivo ‘cellular barcoding’ shows that early haematopoietic progenitors are heterogeneous in the cell types that they produce, and this is partly due to an ‘imprinting’ of fate in progenitors, including for a separate dendritic cell lineage.

    • Shalin H. Naik
    • , Leïla Perié
    •  & Ton N. Schumacher
  • Letter |

    Immunoglobulin genes are expressed from either the maternal or paternal chromosome; it is now shown that in early haematopoietic stem cells, an individual cell can choose either of the two alleles, but as they develop they become committed to only one.

    • Marganit Farago
    • , Chaggai Rosenbluh
    •  & Yehudit Bergman
  • Article |

    A meta-analysis of genome-wide association studies in more than 66,000 individuals identifies 68 new genomic loci that reliably associate with platelet count and volume, and reveals new gene functions.

    • Christian Gieger
    • , Aparna Radhakrishnan
    •  & Nicole Soranzo
  • Letter |

    Here, a new type of behaviour of receptor–ligand bonds has been identified, by using a new method that links receptor and ligand in a single molecule to measure binding and unbinding. The binding of von Willebrand factor to the glycoprotein Ib α subunit on the surface of platelets is important for coagulation. This receptor–ligand bond is now shown to have two distinct states, one seen at low force and a second that has greater force resistance. This has implications for how increased blood flow activates platelet plug formation.

    • Jongseong Kim
    • , Cheng-Zhong Zhang
    •  & Timothy A. Springer
  • Article |

    The identity of the cells that form the haematopoietic stem cell (HSC) niche in bone marrow has been unclear. These authors identify nestin-expressing mesenchymal stem cells as niche-forming cells. These nestin-expressing cells show a close physical association with HSCs and express high levels of genes involved in HSC maintenance, and their depletion reduces bone marrow homing of haematopoietic progenitors.

    • Simón Méndez-Ferrer
    • , Tatyana V. Michurina
    •  & Paul S. Frenette
  • Letter |

    One of two papers showing the generation of haematopoietic stem cells (HSCs) from the ventral wall of the dorsal aorta in live zebrafish embryos. Here, using imaging of live zebrafish, HSCs are shown to emerge directly from the aorta floor. This process does not involve cell division but movement of single endothelial cells out of the aorta ventral wall into the sub aortic space, where they transform into haematopoietic cells.

    • Karima Kissa
    •  & Philippe Herbomel
  • Article |

    Age-associated changes in stem cell supportive niche cells are shown to deregulate normal haematopoiesis by causing haematopoietic stem cell dysfunction. Age-dependent defects in niche cells are systemically regulated and can be reversed by exposure to a young circulation or by neutralization of the conserved longevity regulator, insulin-like growth factor-1, in the marrow microenvironment.

    • Shane R. Mayack
    • , Jennifer L. Shadrach
    •  & Amy J. Wagers