Temporal Variation in Nucleic Acid and Protein Ratios in Four Anthozoan-dinoflagellate Endosymbioses of the Indo-Pacific: Implications for Molecular Diagnostics

印度太平洋四珊瑚綱－雙邊毛藻共生體核苷酸及蛋白質比例隨時間改變對分子檢測法的意義

安德森 梅菲爾得(Anderson B. Mayfield) ； 蕭義勇(Yi-Yuong Hsiao) ； 樊同雲(Tung-Yung Fan) ； 陳啟祥(Chii-Shiarng Chen)

《Platax》 2012卷 (2012/12) Pp. 1-24

https://doi.org/10.29926/PLATAX.201212.0001

摘要

由於全球氣候變遷的影響，主要組成珊瑚礁的珊瑚蟲及共生藻的共生關係正在快速的改變。因此，瞭解對環境改變極度敏感的珊瑚蟲及共生藻生理上如何應對快速氣候變遷為非常急迫的議題。但是，目前對於珊瑚蟲的瞭解依然十分貧乏。尤其是如何與共生藻建立並維持其共生關係依然缺乏深入的瞭解。舉例來說，近來始有研究指出共生關係中的分子成份會隨著時間改變；詳細來說，共生藻的DNA數量會隨著亮暗週期而改變，而此現象會影響基因表現的測量。由於上述理由，有需要同時瞭解分子和蛋白質成份在珊瑚、海葵共生體中隨時間、空間以及物種間的改變。在分析已發表和未發表的數據後，發現總RNA、DNA、蛋白質數量在夏威夷採集的疣表孔珊瑚（Montipora capitata) 、細枝鹿角珊瑚（Pocillopora damicornis）、美麗海葵（Aiptasia puchella）和臺灣海域中的尖支列孔珊瑚（Seriatopora hystrix）中會隨著時間變動。更進一步，可作為基因表現指標的RNA/DNA比例和蛋白質表現指標的蛋白質/DNA比例亦隨著時間而變動。此現象可能由於共生藻密度隨時間改變而造成。綜合上述資料指出在利用分子技術進行珊瑚礁的檢測時，對於數據的品質控管十分的重要；以防止在利用分子生物指標時造成偏差。

關鍵字

珊瑚綱 ； 珊瑚 ； 細胞內共生 ； 基因表現 ； 全球氣候變遷 ； 分子生物 ； 共生藻（Symbiodinium）

並列摘要

Given the threat of global climate change towards coral reefs and the endosymbiotic anthozoans that construct them, there is an urgent need to better understand the physiological response of these environmentally sensitive organisms. Unfortunately, many aspects of anthozoan biology are poorly understood, such as the cellular and molecular mechanisms underlying the stability of their association with dinoflagellates of the genus Symbiodinium. For instance, it has only recently been demonstrated that the molecular composition of these mutualisms is temporally variable; specifically, Symbiodinium DNA content has been shown to vary significantly across the light-dark cycle, and such variation could have implications for normalization of macromolecular expression data. For that reason, there was an interest in better understanding both spatio-temporal and interspecific variation in the concentrations of nucleic acids and proteins in reef-building corals and endosymbiotic sea anemones. Upon exploration of both published and unpublished datasets, it was found that total RNA, DNA, and protein quantities and concentrations were variable over time in the majority of the taxa sampled, which included two reef-building corals (Montipora capitata Hawaii, as well as one Taiwanese scleractinian (Seriatopora hystrix). Furthermore, RNA/DNA and protein/DNA ratios, which can serve as indicators for total levels of gene and protein expression, respectively, also varied over time and across species, and these differences may be due to spatio-temporal variation in Symbiodinium densities driven by heterogeneity in the abiotic environment. Collectively, these data suggest that a high degree of quality control is necessary when employing molecular diagnostics approaches to management of corals and the reefs they build, lest results from biomarker-based endeavors be biased by the potentially unstable biological composition of these globally threatened endosymbioses.

並列關鍵字

anthozoan ； coral ； endosymbiosis ； gene expression ； global climate change ； molecular biology ； Symbiodinium