Richier Sophie, Sabourault Cécile, Courtiade Juliette, Zucchini Nathalie, Allemand Denis, Furla Paola
UMR 1112 UNSA-INRA ROSE, Nice-Sophia Antipolis University, Nice, France.
FEBS J. 2006 Sep;273(18):4186-98. doi: 10.1111/j.1742-4658.2006.05414.x. Epub 2006 Aug 14.
Symbiosis between cnidarian and photosynthetic protists is widely distributed over temperate and tropical seas. These symbioses can periodically breakdown, a phenomenon known as cnidarian bleaching. This event can be irreversible for some associations subjected to acute and/or prolonged environmental disturbances, and leads to the death of the animal host. During bleaching, oxidative stress has been described previously as acting at molecular level and apoptosis is suggested to be one of the mechanisms involved. We focused our study on the role of apoptosis in bleaching via oxidative stress in the association between the sea anemone Anemonia viridis and the dinoflagellates Symbiodinium species. Characterization of caspase-like enzymes were conducted at the biochemical and molecular level to confirm the presence of a caspase-dependent apoptotic phenomenon in the cnidarian host. We provide evidence of oxidative stress followed by induction of caspase-like activity in animal host cells after an elevated temperature stress, suggesting the concomitant action of these components in bleaching.
刺胞动物与光合原生生物之间的共生关系广泛分布于温带和热带海域。这些共生关系可能会周期性地瓦解，这种现象被称为刺胞动物白化。对于一些遭受急性和/或长期环境干扰的共生组合来说，这一事件可能是不可逆的，并会导致动物宿主死亡。在白化过程中，氧化应激此前已被描述为在分子水平起作用，并且细胞凋亡被认为是其中涉及的机制之一。我们的研究聚焦于海葵绿海葵（Anemonia viridis）与甲藻共生菌（Symbiodinium species）之间的共生关系中，细胞凋亡在由氧化应激引发的白化过程中所起的作用。我们在生化和分子水平对类半胱天冬酶进行了表征，以证实刺胞动物宿主中存在依赖半胱天冬酶的凋亡现象。我们提供的证据表明，温度升高胁迫后，动物宿主细胞会出现氧化应激，随后诱导类半胱天冬酶活性，这表明这些成分在白化过程中协同作用。
