20206-06-02 レンセラー工科大学（RPI）
Euplotes gigatrox cell, imaged by scanning electron microscopy (SEM), produced by Ben Larson and Samuel Lord.
＜関連情報＞
- https://news.rpi.edu/2026/06/02/rpi-researcher-discovers-single-celled-organism-transforms-cannibalistic-supergiant
- https://www.pnas.org/doi/10.1073/pnas.2606891123
繊毛虫Euplotes gigatroxにおける共食い性超巨大細胞の制御された発達 Regulated development of cannibalistic supergiant cells in the ciliate Euplotes gigatrox
Ben T. Larson, Daniele Giannotti, Mahara Mtawali, +2 , and Patrick J. Keeling
Proceedings of the National Academy of Sciences Published:May 14, 2026
DOI:https://doi.org/10.1073/pnas.2606891123
Significance
Development in microbial eukaryotes (protists), which can rival the morphological complexity of small animals, is largely unexplored. We report here on the finding that in clonal populations of the ciliate Euplotes gigatrox a small number of cells can develop into cannibalistic “supergiants” that drastically change size, shape, and behavior, transitioning from filter feeders to raptorial predators that can consume their kin. This process involves phenotypic tradeoffs and a system of regulatory loops consistent with a bet-hedging mechanism tuned to fluctuating environmental conditions. Our work introduces insights and approaches for studying morphogenesis and behavior in complex, unicellular organisms, complementing traditional studies of animal evolutionary developmental biology and cell differentiation.
Abstract
Virtually all paradigms in developmental biology apply to differentiating cells and tissues within multicellular animals and plants. However, unicellular eukaryotes, which must simultaneously perform all activities necessary for a cell as well as an organism, also form complex and specialized structures, using exclusively subcellular processes. Here, we describe a ciliate (Euplotes gigatrox sp. nov.) undergoing drastic morphological transformations within a genetically uniform population, the most spectacular being the appearance of “supergiants” that increase in size, change shape, and modify their locomotion and feeding behavior to cannibalize clonal relatives. We explore supergiant formation from the perspective of life cycle, ecological strategy, and gene expression, demonstrating that supergiants are a distinct, regulated, transcriptionally unique stage. Differentiation appears to depend on internal and external conditions, suggesting that regulatory loops have evolved to ensure coupling between environmental and physiological conditions. This system provides a blueprint for approaching both cell differentiation and functional ecology in unicellular organisms, which might open new avenues for the generalization and contextualization of known morphogenetic mechanisms, as well as the discovery of new ones.
