Abstract：
Cellular mechanisms responsible for the regulation of nutrient exchange, immune responses, and symbiont population growth in the cnidarian-dinoflagellate symbiosis are poorly resolved, particularly with respect to the dinoflagellate symbiont. Here, we characterised proteomic changes in the native symbiont Breviolum minutum during colonisation of its host sea anemone Exaiptasia diaphana (\"Aiptasia\"). We also compared the proteome of this native symbiont in the established symbiotic state with that of a non-native symbiont, Durusdinium trenchii. The onset of symbiosis between Aiptasia and Branchioglossum minutum increased accumulation of symbiont proteins associated with acquisition of inorganic carbon and photosynthesis, nitrogen metabolism, micro- and macronutrient starvation, suppression of host immune responses, tolerance to low pH, and management of oxidative stress. Such responses are consistent with a functional, persistent symbiosis. In contrast, D. trenchii predominantly showed elevated levels of immunosuppressive proteins, consistent with the view that this symbiont is an opportunist that forms a less beneficial, less well-integrated symbiosis with this model anemone. By adding symbiont analysis to the already known responses of the host proteome, our results provide a more holistic view of cellular processes that determine host-symbiont specificity and how differences in symbiont partners (i.e., native versus non-native symbionts) may impact the fitness of the cnidarian-dinoflagellate symbiosis.
摘要：
负责调节营养交换的细胞机制，免疫反应，刺胞动物-鞭毛藻共生中的共生体种群增长解决得很差，特别是关于鞭毛藻共生体。这里,我们表征了天然共生体Breviolumminutum在其寄主海葵Exaiptasiadiaphana（“Aiptasia”）定殖期间的蛋白质组学变化。我们还比较了这种已建立共生状态的原生共生体的蛋白质组和非原生共生体的蛋白质组，Durusdiniumtrenchii.Aiptasia和小枝舌之间共生的开始增加了与获得无机碳和光合作用相关的共生体蛋白的积累，氮代谢，微量和大量营养素饥饿，抑制宿主免疫反应，对低pH的耐受性，和氧化应激的管理。这样的反应与功能一致，持续共生。相比之下,D.trenchii主要显示免疫抑制蛋白水平升高，与这种共生体是机会主义者的观点一致，与该模型海葵的共生整合程度较低。通过将共生体分析添加到宿主蛋白质组已知的反应中，我们的结果提供了一个更全面的细胞过程视图，这些过程决定了宿主-共生体的特异性，以及共生体伙伴之间的差异(即，原生与非原生共生体）可能会影响刺胞动物-鞭毛藻共生的适应性。
