Isolation of clonal axenic strains of the symbiotic dinoflagellate Symbiodinium and their growth and host specificity
Isolation of clonal axenic strains of the symbiotic dinoflagellate Symbiodinium and their growth and host specificity
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DOI：
10.1111/jpy.12055
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发表时间：
2013-06-01
影响因子：
2.9
通讯作者：
Grossman, Arthur R.
中科院分区：
文献类型：
--
作者：
Xiang, Tingting;Hambleton, Elizabeth A.;Grossman, Arthur R.
刺胞动物和甲藻的共生关系是珊瑚礁生态系统生存不可或缺的一部分。尽管珊瑚具有巨大的生态和经济重要性，但人们对珊瑚的细胞和分子生物学以及它们对环境变化的反应方式仍然知之甚少。我们一直在开发一个代理系统，研究珊瑚共生的甲藻共生体Symbiodinium引入到一个克隆的主机Aiptasia，一个小海葵密切相关的珊瑚种群。为了进一步开发该系统的工具，我们产生了五个克隆，无菌菌株共生藻，并验证了丰富的培养基上生长，显微镜检查，PCR分析的污染物的缺乏。根据叶绿体23 S rDNA序列将这些菌株分为A（两个菌株）、B、E和F分支。在液体培养物中的生长研究表明，进化枝B菌株和进化枝A菌株之一能够光自养（在没有固定碳的光中）、混合营养（在有固定碳的光中）或异养（在有固定碳的黑暗中）生长。进化枝E菌株被认为是自由生活的，能够光自养生长，但不能异养生长。与无菌菌株的非共生Aiptasia主机的感染表现出一致的模式的特异性，只有分支B和一个分支A菌株能够成功地建立共生。总的来说，Aiptasia共生藻协会是一个重要的模型系统解剖方面的生理和细胞和分子生物学的刺胞藻甲藻共生和探索问题，直接对珊瑚漂白。
The cnidarian-dinoflagellate mutualism is integral to the survival of the coral-reef ecosystem. Despite the enormous ecological and economic importance of corals, their cellular and molecular biology and the ways in which they respond to environmental change are still poorly understood. We have been developing a proxy system for examining the coral mutualism in which the dinoflagellate symbiont Symbiodinium is introduced into a clonal population of the host Aiptasia, a small sea anemone closely related to corals. To further develop the tools for this system, we generated five clonal, axenic strains of Symbiodinium and verified the lack of contaminants by growth on rich medium, microscopic examination, and PCR analysis. These strains were assigned to clades A (two strains), B, E, and F based on their chloroplast 23S rDNA sequences. Growth studies in liquid cultures showed that the clade B strain and one of the clade A strains were able to grow photoautotrophically (in light with no fixed carbon), mixotrophically (in light with fixed carbon), or heterotrophically (in dark with fixed carbon). The clade E strain, thought to be free-living, was able to grow photoautotrophically but not heterotrophically. Infection of an aposymbiotic Aiptasia host with the axenic strains showed consistent patterns of specificity, with only the clade B and one of the clade A strains able to successfully establish symbiosis. Overall, the Aiptasia-Symbiodinium association represents an important model system for dissecting aspects of the physiology and cellular and molecular biology of cnidarian-dinoflagellate mutualism and exploring issues that bear directly on coral bleaching.