Variation in symbiont distribution between closely related coral species over large depth ranges
Variation in symbiont distribution between closely related coral species over large depth ranges
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DOI：
10.1111/j.1365-294x.2007.03612.x
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发表时间：
2008-01-01
影响因子：
4.9
通讯作者：
Bak, R. P. M.
中科院分区：
文献类型：
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作者：
Frade, P. R.;De Jongh, F.;Bak, R. P. M.
分布在大深度范围内的珊瑚物种中的共生藻类面临着光照条件的巨大差异。我们研究了 Madracis 珊瑚属中 Symbiodinium 在深度（5-40 m）和两个不同群体表面位置的遗传变异。使用聚合酶链反应变性梯度凝胶电泳 ITS2 核核糖体 DNA 分析，我们一致地鉴定了三种共生体基因型，其分布揭示了宿主特异性和基于深度的分区模式。 ITS2 B7 型共生藻是多面性类型，存在于所有虫黄藻马德拉西斯珊瑚中和所有深度。 B13 型仅限于浅水专家 Madracis mirabilis。 B15 型是典型的深礁环境，在深度通才 Madracis pharensis 中取代了 B7。与深度的变化相比，我们发现共生体多样性具有很强的功能一致性。将共生体分布与测量的物理因素（辐照度、光谱分布、温度）联系起来，表明共生藻 ITS2 类型具有基于深度的生态功能和宿主特异性，即使在密切相关的珊瑚物种中也是如此。
Symbiotic algae in coral species distributed over a large depth range are confronted with major differences in light conditions. We studied the genetic variation of Symbiodinium in the coral genus Madracis over depth (5-40 m) and at two different colony surface positions. Using polymerase chain reaction-denaturing gradient gel electrophoresis ITS2 nuclear ribosomal DNA analyses, we consistently identified three symbiont genotypes with distributions that reveal patterns of host specificity and depth-based zonation. ITS2 type B7 Symbiodinium is the generalist type, occurring in all zooxanthellate Madracis corals and at all depths. Type B13 is restricted to the shallow water specialist Madracis mirabilis. Type B15 is typical of deep reef environments and replaces B7 in the depth generalist Madracis pharensis. Contrasting with variation over depth, we found strong functional within-colony uniformity in symbiont diversity. Relating symbiont distributions to measured physical factors (irradiance, light spectral distribution, temperature), suggests depth-based ecological function and host specificity for Symbiodinium ITS2 types, even among closely related coral species.