Pattern formation

  • 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 |

    Cryo-electron microscopy studies show that dynamic coordination of Na+ in the ion channel of Dispatched homologue 1 and the transmembrane Na+ gradient have key roles in exporting lipid-modified Hedgehog protein signal.

    • Qianqian Wang
    • , Daniel E. Asarnow
    •  & Philip A. Beachy
  • Article |

    Genetic studies in Drosophila combined with structural analyses show that glypicans bind palmitoylate moieties in Wnt ligands, and thus shield Wnt ligands from their aqueous environments to enable them to signal to their distant receptors.

    • Ian J. McGough
    • , Luca Vecchia
    •  & Jean-Paul Vincent
  • Article |

    Single-cell RNA sequencing and spatial transcriptomics reveal that the somitogenesis clock is active in mouse gastruloids, which can be induced to generate somites with the correct rostral–caudal patterning.

    • Susanne C. van den Brink
    • , Anna Alemany
    •  & Alexander van Oudenaarden
  • Article |

    Monitoring cells of the mouse presomitic mesoderm using the Achilles reporter fused to HES7 sheds light on the mechanisms that underpin synchronous oscillations in the expression of clock genes between neighbouring cells.

    • Kumiko Yoshioka-Kobayashi
    • , Marina Matsumiya
    •  & Ryoichiro Kageyama
  • Article |

    Human presomitic mesoderm cells derived in vitro demonstrate oscillations of the segmentation clock, thus providing a window into an otherwise inaccessible stage of human development.

    • Margarete Diaz-Cuadros
    • , Daniel E. Wagner
    •  & Olivier Pourquié
  • Letter |

    A mouse blastocyst model reveals how lumenal pressure, cell cortical tension and tissue stiffness act at the tissue scale to regulate embryo size, which in turn influences the division pattern of trophectoderm cells and their fate specification.

    • Chii Jou Chan
    • , Maria Costanzo
    •  & Takashi Hiiragi
  • Letter |

    Stimulation of Wnt and Nodal pathways in micropatterned human embryonic stem cell colonies induce these colonies to exhibit characteristic spatial expression patterns of the organizer and reproduce organizer function when grafted into a host embryo.

    • I. Martyn
    • , T. Y. Kanno
    •  & A. H. Brivanlou
  • Letter |

    Live imaging and single-cell analyses are used to show that decision-making by differentiating haematopoietic stem cells between the megakaryocytic–erythroid and granulocytic–monocytic lineages is not initiated by stochastic switching between the lineage-specific transcription factors PU.1 and GATA1, which challenges the previous model of early myeloid lineage choice.

    • Philipp S. Hoppe
    • , Michael Schwarzfischer
    •  & Timm Schroeder
  • Letter |

    Butterflies diversify their retinal mosaics by producing three stochastic types of ommatidia instead of the two types found in Drosophila; this study shows that butterfly retinas use two R7-like photoreceptors per ommatidium that each make an independent stochastic decision to express the transcription factor Spineless, which controls photoreceptor and ommatidial fate.

    • Michael Perry
    • , Michiyo Kinoshita
    •  & Claude Desplan
  • Article |

    The morphogen Decapentaplegic (Dpp) has been implicated in both wing patterning and growth in fruitflies; here, a nanobody-based morphotrap approach has been developed that rules out a role for the Dpp gradient in regulating lateral wing growth.

    • Stefan Harmansa
    • , Fisun Hamaratoglu
    •  & Emmanuel Caussinus
  • Article |

    Specialized ribosomes (with a particular protein composition) carry out translation of specific transcripts; analysis of Hox mRNA translation in mice reveals that unique RNA structural elements within their 5′ UTRs, including internal ribosome entry sites and translation inhibitory elements, are responsible for this specialized mode of translation.

    • Shifeng Xue
    • , Siqi Tian
    •  & Maria Barna
  • Letter |

    Nested Hox expression domains are found in jawed vertebrates and in non-vertebrate chordates, but it is unclear whether there is a link between brain regionalization and Hox expression in jawless vertebrates; here, Hox expression is shown to be integrated with hindbrain segmentation in lampreys.

    • Hugo J. Parker
    • , Marianne E. Bronner
    •  & Robb Krumlauf
  • Article |

    Replacement of the wingless (wg) gene in Drosophila with one that expresses a membrane-tethered form of Wg results in viable flies with normally patterned appendages of nearly the right size; early wg transcription and memory of signalling ensure continued target-gene expression in the absence of Wg release, even though the spread of Wg could boost cell proliferation.

    • Cyrille Alexandre
    • , Alberto Baena-Lopez
    •  & Jean-Paul Vincent
  • Letter |

    This study uses single-cell real-time imaging to show that sonic hedgehog (SHH) is produced in the form of a particle that is transported along a novel class of specialized actin-based filopodia spanning several cell diameters within the field of SHH cell signalling, thus expanding our knowledge of ligand movement during normal vertebrate development.

    • Timothy A. Sanders
    • , Esther Llagostera
    •  & Maria Barna
  • Letter |

    An ex vivo primary culture assay is developed that recapitulates mouse embryonic mesodermal patterning and segment formation; using this approach, it is shown that oscillating gene activity is central to maintain stable proportions during development.

    • Volker M. Lauschke
    • , Charisios D. Tsiairis
    •  & Alexander Aulehla
  • Letter |

    The blood–brain barrier (BBB) is made up of vascular endothelial cells and was thought to have formed postnatally from astrocytes. Two independent studies demonstrate that this barrier forms during embryogenesis, with pericyte/endothelial cell interactions being critical to regulate the BBB during development. A better understanding of the relationship among pericytes, neuroendothelial cells and astrocytes in BBB function will contribute to our understanding of BBB breakdown during central nervous system injury and disease.

    • Annika Armulik
    • , Guillem Genové
    •  & Christer Betsholtz
  • Letter |

    In higher animals and plants, the processes of growth and patterning are coordinated. In this study, the authors study patterning in Arabidopsis root and show that two key regulators of root organ patterning directly control the transcription of specific components of the cell-cycle machinery. This study provides a direct link between developmental regulators, components of the cell-cycle machinery and organ patterning.

    • R. Sozzani
    • , H. Cui
    •  & P. N. Benfey
  • Article |

    Here, the generation and evolution of the complex spotted wing pattern of Drosophila guttifera are investigated. The findings show that wing spots are induced by the Wingless morphogen, and that the elaborate spot pattern evolved from simpler schemes by co-option of Wingless expression at new sites. This type of process is likely to occur in other animals, too.

    • Thomas Werner
    • , Shigeyuki Koshikawa
    •  & Sean B. Carroll
  • Letter |

    The organization of Hox clusters in several different reptiles is investigated, showing that the Hox clusters in squamates — lizards and snakes — have unexpectedly accumulated transposable elements, reflecting extensive genomic rearrangements of coding and non coding regulatory regions. Comparative expression analyses between two species showing different axial skeletons, the corn snake and the whiptail lizard, revealed major alterations in Hox13 and Hox10 expression features during snake somitogenesis, in line with the expansion of both caudal and thoracic regions.

    • Nicolas Di-Poï
    • , Juan I. Montoya-Burgos
    •  & Denis Duboule
  • Letter |

    The vertebrate body plan shows marked bilateral symmetry, although this can be disrupted in conditions such as scoliosis. Here, a mutation in Rere is found that leads to the formation of asymmetrical somites in mouse embryos; furthermore, Rere is shown to control retinoic acid signalling, which is required to maintain somite symmetry by interacting with Fgf8. The results provide insight into how bilateral symmetry is maintained.

    • Gonçalo C. Vilhais-Neto
    • , Mitsuji Maruhashi
    •  & Olivier Pourquié