Rowan R, Powers D A
Department of Biological Sciences, Stanford University, Pacific Grove, CA 93950-3094.
Proc Natl Acad Sci U S A. 1992 Apr 15;89(8):3639-43. doi: 10.1073/pnas.89.8.3639.
Zooxanthellae are unicellular algae that occur as endosymbionts in many hundreds of common marine invertebrates. The issue of zooxanthella diversity has been difficult to address. Most zooxanthellae have been placed in the dinoflagellate genus Symbiodinium as one or several species that are not easily distinguished. We compared Symbiodinium and nonsymbiotic dinoflagellates using small ribosomal subunit RNA sequences. Surprisingly, small ribosomal subunit RNA diversity within the genus Symbiodinium is comparable to that observed among different orders of nonsymbiotic dinoflagellates. These data reinforce the conclusion that Symbiodinium-like zooxanthellae represent a collection of distinct species and provide a precedent for a molecular genetic taxonomy of the genus Symbiodinium.
虫黄藻是单细胞藻类，作为内共生体存在于数百种常见海洋无脊椎动物中。虫黄藻的多样性问题一直难以解决。大多数虫黄藻被归入甲藻纲的共生藻属，作为一个或几个不易区分的物种。我们使用小核糖体亚基RNA序列比较了共生藻属和非共生甲藻。令人惊讶的是，共生藻属内的小核糖体亚基RNA多样性与在不同甲藻目非共生甲藻中观察到的多样性相当。这些数据强化了这样的结论，即类似共生藻的虫黄藻代表了不同物种的集合，并为共生藻属的分子遗传分类学提供了一个先例。
