He Lily S, Qi Yujia, Allard Corey Ah, Valencia-Montoya Wendy A, Krueger Stephanie P, Weir Keiko, Seminara Agnese, Bellono Nicholas W
Department of Molecular and Cellular Biology, Harvard University, Cambridge MA 02138 USA.
Machine Learning Center Genoa (MalGa), Department of Civil, Chemical and Environmental Engineering (DICCA), University of Genoa, Via Montallegro 1, 16145 Genoa, Italy.
bioRxiv. 2023 Sep 26:2023.06.15.545144. doi: 10.1101/2023.06.15.545144.
Jellyfish and sea anemones fire single-use, venom-covered barbs to immobilize prey or predators. We previously showed that the anemone uses a specialized voltage-gated calcium (Ca) channel to trigger stinging in response to synergistic prey-derived chemicals and touch (Weir et al., 2020). Here we use experiments and theory to find that stinging behavior is suited to distinct ecological niches. We find that the burrowing anemone uses uniquely strong Ca inactivation for precise control of predatory stinging. In contrast, the related anemone inhabits exposed environments to support photosynthetic endosymbionts. Consistent with its niche, indiscriminately stings for defense and expresses a Ca splice variant that confers weak inactivation. Chimeric analyses reveal that Caβ subunit adaptations regulate inactivation, suggesting an evolutionary tuning mechanism for stinging behavior. These findings demonstrate how functional specialization of ion channel structure contributes to distinct organismal behavior.
水母和海葵会发射一次性的、覆盖毒液的倒刺来制服猎物或捕食者。我们之前表明，海葵利用一种特殊的电压门控钙（Ca）通道，以响应协同的猎物衍生化学物质和触摸来触发刺痛（韦尔等人，2020年）。在这里，我们通过实验和理论发现，刺痛行为适合不同的生态位。我们发现，穴居海葵利用独特的强钙失活来精确控制捕食性刺痛。相比之下，相关的海葵栖息在暴露的环境中以支持光合内共生体。与其生态位一致，它为了防御而不加区分地刺痛，并表达一种导致弱失活的钙剪接变体。嵌合分析表明，Caβ亚基的适应性调节失活，这表明存在一种针对刺痛行为的进化调节机制。这些发现证明了离子通道结构的功能特化如何导致不同的生物体行为。
