Ulstrup K E, Van Oppen M J H
Department of Phycology, Botanical Institute, University of Copenhagen, Copenhagen, Denmark.
Mol Ecol. 2003 Dec;12(12):3477-84. doi: 10.1046/j.1365-294x.2003.01988.x.
Intra- and intercolony diversity and distribution of zooxanthellae in acroporid corals is largely uncharted. In this study, two molecular methods were applied to determine the distribution of zooxanthellae in the branching corals Acropora tenuis and A. valida at several reef locations in the central section of the Great Barrier Reef. Sun-exposed and shaded parts of all colonies were examined. Single-stranded conformational polymorphism analysis showed that individual colonies of A. tenuis at two locations harbour two strains of Symbiodinium belonging to clade C (C1 and C2), whereas conspecific colonies at two other reefs harboured a single zooxanthella strain. A. valida was found to simultaneously harbour strains belonging to two distinct phylogenetic clades (C and D) at all locations sampled. A novel method with improved sensitivity (quantitative polymerase chain reaction using Taqman fluorogenic probes) was used to map the relative abundance distribution of the two zooxanthella clades. At two of the five sampling locations both coral species were collected. At these two locations, composition of the zooxanthella communities showed the same pattern in both coral species, i.e. correlation with ambient light in Pioneer Bay and an absence thereof in Nelly Bay. The results show that the distribution of genetically distinct zooxanthellae is correlated with light regime and possibly temperature in some (but not all) colonies of A. tenuis and A. valida and at some reef locations, which we interpret as acclimation to local environmental conditions.
鹿角珊瑚群体内和群体间虫黄藻的多样性及分布情况在很大程度上尚不清楚。在本研究中，应用了两种分子方法来确定大堡礁中部几个珊瑚礁地点的分支珊瑚细枝鹿角珊瑚和强壮鹿角珊瑚中虫黄藻的分布。对所有珊瑚群体的受光和遮光部分都进行了检查。单链构象多态性分析表明，两个地点的细枝鹿角珊瑚个体群体含有属于C类（C1和C2）的两种共生藻菌株，而另外两个珊瑚礁的同种珊瑚群体则只含有一种虫黄藻菌株。在所有采样地点，强壮鹿角珊瑚被发现同时含有属于两个不同系统发育类群（C和D）的菌株。一种具有更高灵敏度的新方法（使用Taqman荧光探针的定量聚合酶链反应）被用于绘制两种虫黄藻类群的相对丰度分布图。在五个采样地点中的两个地点采集了这两种珊瑚。在这两个地点，两种珊瑚的虫黄藻群落组成呈现出相同的模式，即在先锋湾与环境光相关，而在内利湾则不存在这种相关性。结果表明,在细枝鹿角珊瑚和强壮鹿角珊瑚的部分（但不是全部）群体以及一些珊瑚礁地点，基因不同的虫黄藻分布与光照条件以及可能的温度相关，我们将此解释为对当地环境条件的适应。
