This paper describes the procedures used to purify the microtubule motor, kinesin, from mitotic cells, namely sea urchin eggs and cleavage stage embryos, and describes methods for assaying its motor activity.

Design features that ensure reproducible and invariant embryonic processes are major characteristics of current gene regulatory network models. New cis-regulatory studies on a gene regulatory network subcircuit activated early in the development of the sea urchin embryo reveal a sequence of encoded "fail-safe" regulatory devices. These ensure the maintenance of fate separation between skeletoge...

While we frequently observe that increasing species richness within a trophic level can increase the rates of predation or herbivory on lower trophic levels, the general impacts of prey diversity on consumption rates by their predators or herbivores remains unclear. Here we report the results of two field experiments that examined how subcanopy sessile species richness affects rates of consumpt...

The kinetics of the regeneration of cilia of the sea urchin Tripneutes gratilla have been examined. The maximum cilia length is attained asymptotically which may reflect the transport of precursors to the distal tip. However, a detailed analysis indicates that the maximum length is regulated by a mechanism other than the availability of precursors at the distal end. It is argued that this contr...

David McClay is the Arthur S. Pearse Professor of Biology at Trinity College of Arts and Sciences, Duke University, North Carolina. His lab works on the transcriptional control of morphogenesis in the sea urchin embryo. We caught up with David at the 2016 Society for Developmental Biology - International Society of Differentiation joint meeting in Boston, where he received the Lifetime Achievem...

Recent studies of the sea urchin embryo have elucidated the mechanisms that localize and pattern its nervous system. These studies have revealed the presence of two overlapping regions of neurogenic potential at the beginning of embryogenesis, each of which becomes progressively restricted by separate, yet linked, signals, including Wnt and subsequently Nodal and BMP. These signals act to speci...

There was an error published in Development 143, 1523-1533. The author affiliations should have been listed as follows. Ryan C. Range and Zheng Wei Department of Biological Sciences, Mississippi State University, Mississippi State, MS 39762, USA. National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892, USA. We apologise to the authors and reader...

Disturbances are natural features of ecosystems that promote variability in the community and ultimately maintain diversity. Although it is recognized that global change will affect environmental disturbance regimes, our understanding of the community dynamics governing ecosystem recovery and the maintenance of functional diversity in future scenarios is very limited. Here, we use one of the fe...

Modeling of specification events during development poses new challenges to biochemical modeling. These include data limitations and a notorious absence of homeostasis in developing systems. The sea urchin is one of the best studied model organisms concerning development and a network, the Endomesoderm Network, has been proposed that is presumed to control endoderm and mesoderm specification in...