Nematocysts are explosive organelles found in all Cnidaria. Explosion of nematocyst capsules is driven by the high pressure within the capsule formed by the high concentration of poly-γ-glutamate in the capsule matrix. Poly-γ-glutamate is a polyanion that binds cations tightly, including the fluorescent cationic dyes acridine orange and DAPI(4′,6-diamidino-2-phenylindole). We have used acridine orange and DAPI staining to localize poly-γ-glutamate within capsules and to follow the biosynthesis of poly-γ-glutamate during capsule formation. The results indicate that poly-γ-glutamate biosynthesis occurs late in capsule formation after invagination of the tubule and that it is accompanied by swelling of the capsule due to increasing osmotic pressure. The matrix in all four capsule types is homogeneously filled with poly-γ-glutamate. In vivo this poly-γ-glutamate is complexed with monovalent cations. In addition, poly-γ-glutamate is formed within the tubule lumen of stenoteles. We argue that this poly-γ-glutamate is required to drive the two-step explosion process in stenotele nematocysts.
Interviews with Biologists @ 100 conference speakers
Explore our interviews with keynote speakers from the Biologists @ 100 conference, hosted to celebrate our publisher’s 100th anniversary, where we discuss climate change and biodiversity with Hans-Otto Pörtner and Jane Francis, health and disease with Charles Swanton and Sadaf Farooqi, and emerging technologies with Manu Prakash and Jennifer Lippincott-Schwartz.
Introducing our new Associate Editors
In this Editorial, JCS Editor-in-Chief Michael Way welcomes five new Associate Editors to the JCS team. These Associate Editors will expand our support for the wider cell biology community and handle articles in immune cell biology, proteostasis, imaging and image analysis, plant cell biology, and stem cell biology and modelling.
The spatial choreography of mRNA biosynthesis
In their Review, André Ventura-Gomes and Maria Carmo-Fonseca detail the latest research progress and technological advancements that are helping to unlock how nuclear organisation underpins control of gene transcription and pre-mRNA splicing.
JCS-FocalPlane Training Grants
Early-career researchers - working in an area covered by JCS - who would like to attend a microscopy training course, please apply. Deadline dates for 2025 applications: 6 June 2025 (decision by week commencing 28 July 2025) and 5 September 2025 (decision by week commencing 20 October 2025).
The emerging roles of the endoplasmic reticulum in mechanosensing and mechanotransduction
In their Review, Jonathan Townson and Cinzia Progida highlight recently emerging evidence for a role of the endoplasmic reticulum in enabling a cell to sense and respond to changes in the extracellular mechanical environment.
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