• Article |

    The rate of scale regeneration in zebrafish is controlled by the frequency of rhythmic travelling waves of Erk activity, which are broadcast from a central source to induce ring-like patterns of osteoblast tissue growth.

    • Alessandro De Simone
    • , Maya N. Evanitsky
    •  & Stefano Di Talia
  • Article |

    Differences in the mechanical properties of individual cardiomyocytes drive their segregation into compact versus trabecular layer, thereby transforming the myocardium in a developing heart from a simple epithelium into an intricately patterned tissue with distinct cell fates.

    • Rashmi Priya
    • , Srinivas Allanki
    •  & Didier Y. R. Stainier
  • Article |

    Miniature gut tubes grown in vitro from mouse intestinal stem cells are perfusable, can be colonized with microorganisms and exhibit a similar arrangement and diversity of specialized cell types to intestines in vivo.

    • Mikhail Nikolaev
    • , Olga Mitrofanova
    •  & Matthias P. Lutolf
  • Article |

    Nodal signalling coordinates embryonic development before and during gastrulation by directing perforation of the basement membrane via spatiotemporal regulation of matrix metalloprotease expression.

    • Christos Kyprianou
    • , Neophytos Christodoulou
    •  & Magdalena Zernicka-Goetz
  • 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 |

    Tissue shape changes in the posterior endoderm of the early Drosophila embryo are driven by actomyosin contractions emerging from a transcriptional induction followed by a mechanically-driven propagation of RhoI–myosin II activation.

    • Anaïs Bailles
    • , Claudio Collinet
    •  & Thomas Lecuit
  • 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
  • Article |

    Cell competition in the developing mouse epithelium involves apoptosis and engulfment when the epithelium has only one layer, but switches to involve asymmetric cell division and differentiation of ‘loser’ cells as the epithelium becomes stratified.

    • Stephanie J. Ellis
    • , Nicholas C. Gomez
    •  & Elaine Fuchs
  • Letter |

    In the red flour beetle (Tribolium castaneum) and fruit fly (Drosophila melanogaster), spatiotemporally coordinated integrin-dependent attachments between the blastoderm and vitelline envelope counteract tissue-intrinsic contractile forces to create asymmetric movements of embryonic tissue.

    • Stefan Münster
    • , Akanksha Jain
    •  & Pavel Tomancak
  • Letter |

    Cell-labelling experiments are used to demonstrate that the hindgut in the chick embryo is formed by cells moving through the stationary caudal intestinal portal as a result of a contractile force gradient directed by fibroblast growth factor signalling.

    • Nandan L. Nerurkar
    • , ChangHee Lee
    •  & Clifford J. Tabin
  • 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 |

    Exit of epiblasts from an unrestricted naive pluripotent state is required for epithelialization and generation of the pro-amniotic cavity in mouse embryos and for amniotic cavity formation in human embryos and human embryonic stem cells.

    • Marta N. Shahbazi
    • , Antonio Scialdone
    •  & Magdalena Zernicka-Goetz
  • Letter |

    Two parallel signalling pathways, driven by Nodal and BMP, respectively integrate left- and right-handed information that drives heart looping and morphogenesis, and are conserved between zebrafish, chicken and mouse.

    • Oscar H. Ocaña
    • , Hakan Coskun
    •  & M. Angela Nieto
  • Article |

    Alx3-induced modulation of Mitf expression alters melanocyte differentiation and gives rise to the hair colour differences underlying the repeated evolution of dorsal stripes in rodents.

    • Ricardo Mallarino
    • , Corneliu Henegar
    •  & Hopi E. Hoekstra
  • Letter |

    Hoxa- and Hoxd-deficient zebrafish generated using Crispr/Cas with fate mapping have reduced fin rays and increased endochondral elements, establishing homology between the developmental programs that create fin rays and the wrists and digits of mammals.

    • Tetsuya Nakamura
    • , Andrew R. Gehrke
    •  & Neil H. Shubin
  • Letter |

    D’Arcy Thompson predicted a century ago that animal body shape is conditioned by gravity, but there has been no animal model to study how cellular forces are coordinated to generate body shapes that withstand gravity; the hirame medaka fish mutant, with pronounced body flattening, reveals how the hirame/YAP gene controls gravity-resisting cellular forces to produce complex 3D organs and body shapes.

    • Sean Porazinski
    • , Huijia Wang
    •  & Makoto Furutani-Seiki
  • Letter |

    Apoptotic cell death is required for morphogenesis of the developing leg joint of fruitflies; using this model system, the authors show here that within apoptotic cells a transient pulling force exerted through a highly dynamic apico-basal myosin II cable-like structure acts as a mechanical signal to increase tissue tension and modify tissue shape.

    • Bruno Monier
    • , Melanie Gettings
    •  & Magali Suzanne
  • Article |

    Body axis elongation from head to tail is essential for animal development, however, the spatial cues that direct cell rearrangements relative to the anterior–posterior axis were unknown; this Drosophila study of convergent extension reveals that three Toll family receptors, expressed in overlapping stripes, modulate the contractile properties of cells to generate the polarized cell rearrangements that lead to body axis elongation.

    • Adam C. Paré
    • , Athea Vichas
    •  & Jennifer A. Zallen
  • Letter |

    The Drosophila tumour suppressors Scribbled and Discs large 1 are found to be essential regulators of planar spindle alignment during epithelial cell division; aberrant effects of spindle alignment are shown to be corrected through apoptosis, and the suppression of this mechanism can result in epithelial dysplasia and tumorigenesis.

    • Yu-ichiro Nakajima
    • , Emily J. Meyer
    •  & Matthew C. Gibson
  • Letter |

    Opaque tissues provide a challenge for live imaging of Xenopus laevis development; a problem solved by in vivo time-lapse X-ray microtomography that is shown to provide a high-resolution three-dimensional view of structural changes and dynamics of gastrulation, and that is applied to identify and analyse new aspects of gastrulation in frog embryos.

    • Julian Moosmann
    • , Alexey Ershov
    •  & Ralf Hofmann
  • Letter |

    Tooth development is used as a model to examine which aspects of phenotype can be optimized by natural selection; this reveals that the complexity of the relationship between genotypic and phenotypic variation can affect adaptation

    • Isaac Salazar-Ciudad
    •  & Miquel Marín-Riera
  • Letter |

    Genetically encoded probes for the non-peptidic morphogen retinoic acid allow the quantitative measurement of physiological RA concentration in vivo; the results support the source–sink diffusion model of morphogen dynamics proposed by Francis Crick in 1970.

    • Satoshi Shimozono
    • , Tadahiro Iimura
    •  & Atsushi Miyawaki
  • Letter |

    Drosophila epithelial tracheal placode invagination is shown to be driven by mitotic cell rounding along with epithelial growth factor receptor signalling and myosin contractility in neighbouring cells, revealing a new cell-division-independent role for mitotic events in morphogenesis.

    • Takefumi Kondo
    •  & Shigeo Hayashi
  • Letter |

    As it develops from a single-celled zygote to a mature plant embryo, the thale cress Arabidopsis thaliana passes through a stage during which phylogenetically very ancient genes are preferentially expressed, showing that animals and plants have independently acquired the developmental hourglass as a similar way of managing gene expression as they pass through embryogenesis, even though their morphological development is very different.

    • Marcel Quint
    • , Hajk-Georg Drost
    •  & Ivo Grosse
  • Article |

    Using a conditional multicolour tracing approach, the contributions of individual cardiomyocytes to zebrafish heart morphogenesis are defined, revealing clonal dominance as a key mechanism.

    • Vikas Gupta
    •  & Kenneth D. Poss
  • Article |

    Organogenesis relies on the orchestration of many cellular interactions to create the collective cell behaviours that progressively shape developing tissues. Using a three-dimensional embryonic stem cell culture system, this study successfully generated neural retinal tissues that formed a fully stratified neural retinal structure with all the major components located in their proper spatial location as seen during optic-cup development in vivo. This approach might have important implications for stem cell therapy for retinal repair.

    • Mototsugu Eiraku
    • , Nozomu Takata
    •  & Yoshiki Sasai
  • Letter |

    This study describes a mechanotransduction pathway that links the body wall with the epidermis in Caenorhabditis elegans. The pathway involves the p21 activated kinase PAK 1, an adaptor GIT 1 and its partner PIX 1. Tension exerted by muscles or external pressure keeps GIT 1 on station at hemidesmosomes — the small rivet like bodies that attach epidermal cells to the underlying musculature — and stimulates PAK 1 through PIX 1 and Rac GTPase. The C. elegans hemidesmosome is more than a passive attachment structure, therefore, but a sensor that responds to tension by triggering signalling processes.

    • Huimin Zhang
    • , Frédéric Landmann
    •  & Michel Labouesse
  • Letter |

    Using a temporal series of growth factor manipulations to mimic embryonic intestinal development in culture, this study has successfully directed the differentiation of human pluripotent stem cells (both embryonic stem cells and induced pluripotent stem cells) into intestinal tissue. This approach may provide therapeutic benefit for disease studies.

    • Jason R. Spence
    • , Christopher N. Mayhew
    •  & James M. Wells
  • Letter |

    For two hundred years, scientists have noticed that the appearance of embryos in related species converge in their appearance mid-way in development, diverging thereafter. But is this 'phylotypic stage' real, and how is it connected with the genetic basis of development? Here, a method linking the genes transcribed at various stages of development (the transcriptome) with the evolutionary history of those genes is used. Genes transcribed in the phylotypic stage are, in evolutionary terms, the oldest and most conserved. This suggests that the phylotypic stage does represent the body plans of related species at their most unadorned, selection having sculpted the earlier and later stages of embryonic form to suit the particulars of each creature.

    • Alex T. Kalinka
    • , Karolina M. Varga
    •  & Pavel Tomancak
  • Letter |

    Here, germ-band extension in Drosophila is studied in which epithelial cells undergo an ordered process of intercalation resulting in tissue extension through remodelling of cell junctions. Cell junction shrinkage is driven by polarized flow of medial Myosin-II pulses towards junctions which organizes the whole process of intercalation. The flow of Myosin II is driven by the polarized distribution of E-cadherin complexes at adherens junctions. Thus, epithelial morphogenesis is driven by polarized contractile actomyosin flows emerging from interactions between E-cadherin and actomyosin networks.

    • Matteo Rauzi
    • , Pierre-François Lenne
    •  & Thomas Lecuit