Development and Symbiosis Establishment in the Cnidarian Endosymbiosis Model Aiptasia sp.
Development and Symbiosis Establishment in the Cnidarian Endosymbiosis Model Aiptasia sp.
复制标题
DOI：
10.1038/srep19867
复制
发表时间：
2016-01-25
影响因子：
4.6
通讯作者：
Guse A
中科院分区：
文献类型：
--
作者：
Bucher M;Wolfowicz I;Voss PA;Hambleton EA;Guse A
光合藻类和异养生物之间的共生现象很普遍。高度生态相关性的一个突出例子是共生藻属的甲藻和造礁珊瑚之间的内共生，它们通常在幼虫阶段每一代都会重新获得共生体。热带海葵 Aiptasia sp.是这种内共生的实验室模型系统，与珊瑚类似，产生非共生幼虫，通过将环境中的共生藻吞噬到内胚层中来建立共生。在这里，我们对 Aiptasia 胚胎发生和幼虫发育进行了首次概述，并建立了原位杂交来分析关键早期发育调节因子的表达模式。接下来，我们量化发育中幼虫的形态变化，并发现胃腔随着时间的推移而大幅扩大。嘴形成后不久，共生体就开始获得，共生体占据了它们所在宿主细胞的主要部分。在发育的前 14 天，感染效率保持恒定，而相反，吞噬共生体的定位发生变化，表明功能性吞噬细胞的出现可能受到发育调节。综上所述，我们在这里提供了进一步开发 Aiptasia 作为模型系统的基本框架，用于在分子水平上分析刺胞动物幼虫的共生建立。
Symbiosis between photosynthetic algae and heterotrophic organisms is widespread. One prominent example of high ecological relevance is the endosymbiosis between dinoflagellate algae of the genus Symbiodinium and reef-building corals, which typically acquire symbionts anew each generation during larval stages. The tropical sea anemone Aiptasia sp. is a laboratory model system for this endosymbiosis and, similar to corals, produces non-symbiotic larvae that establish symbiosis by phagocytosing Symbiodinium from the environment into the endoderm. Here we generate the first overview of Aiptasia embryogenesis and larval development and establish in situ hybridization to analyze expression patterns of key early developmental regulators. Next, we quantify morphological changes in developing larvae and find a substantial enlargement of the gastric cavity over time. Symbiont acquisition starts soon after mouth formation and symbionts occupy a major portion of the host cell in which they reside. During the first 14 days of development, infection efficiency remains constant while in contrast, localization of phagocytosed symbionts changes, indicating that the occurrence of functional phagocytosing cells may be developmentally regulated. Taken together, here we provide the essential framework to further develop Aiptasia as a model system for the analysis of symbiosis establishment in cnidarian larvae at the molecular level.