Cell fates in sea urchin embryos are remarkably labile. For example,mesodermal lineages can activate the transcriptional gene regulatory network(GRN) that drives skeletogenesis if the micromere precursors of the primary mesenchyme cells (PMCs, the cells that form the embryonic skeleton) are removed. To determine the molecular basis of this plasticity, Ettensohn and colleagues have examined the conversion of non-skeletogenic mesoderm (NSM) to a PMC fate during gastrulation and reveal that most, but not all, of the upstream transcription factors in the skeletogenic GRN are recapitulated by transfating cells (see p. 3077). They show that the transcription factor alx1, a key component of the skeletogenic GRN, is expressed in transfating NSMs, that alx1 expression in transfating NSMs and in PMCs requires MAPK signalling, and that alx1 expression in micromeres normally suppresses NSMs from transfating. However, the transcription factor pmar1 (which activates the skeletogenic GRN in PMCs) is not needed in transfating NSMs. Thus, the skeletogenic GRN is activated by distinct mechanisms during normal and regulative development.
Network deployments for developmental plasticity
Network deployments for developmental plasticity. Development 1 September 2007; 134 (17): e1703. doi:
Download citation file:
Advertisement
Cited by
Biologists @ 100 - join us in Liverpool in March 2025

We are excited to invite you to a unique scientific conference, celebrating the 100-year anniversary of The Company of Biologists, and bringing together our different communities. The conference will incorporate the Spring Meetings of the BSCB and the BSDB, the JEB Symposium Sensory Perception in a Changing World and a DMM programme on antimicrobial resistance. Find out more and register by 28 February 2025 to join us in March 2025 in Liverpool, UK.
Call for papers – Lifelong Development: the Maintenance, Regeneration and Plasticity of Tissues

Development invites you to submit your latest research to our upcoming special issue – Lifelong Development: the Maintenance, Regeneration and Plasticity of Tissues. This issue will be coordinated by Guest Editors Meritxell Huch (Max Planck Institute of Molecular Cell Biology and Genetics, Germany) and Mansi Srivastava (Harvard University and Museum of Comparative Zoology, USA), working alongside our team of academic Editors. Submit your articles by 15 May 2025.
A case for broadening our view of mechanism in developmental biology

In this Perspective, B. Duygu Özpolat and colleagues survey researchers on their views on what it takes to infer mechanism in developmental biology. They examine what factors shape our idea of what we mean by ‘mechanism’ and suggest a path forward that embraces a broad outlook on the diversity of studies that advance knowledge in our field.
In preprints
Did you know that Development publishes perspectives on recent preprints? These articles help our readers navigate the ever-growing preprint literature. We welcome proposals for ‘In preprints’ articles, so please do get in touch if you’d like to contribute.