Feldman R A, Black M B, Cary C S, Lutz R A, Vrijenhoek R C
Center for Theoretical and Applied Genetics, Cook College, Rutgers University, New Brunswick, New Jersey, USA.
Mol Mar Biol Biotechnol. 1997 Sep;6(3):268-77.
Vestimentiferan tube worms from deep-sea hydrothermal vents and cold-water seeps rely entirely on sulfur-oxidizing bacterial endosymbionts for nutriment. We examined host-symbiont co-evolution by comparing phylogenetic trees from symbiont 16S ribosomal DNA and host mitochondrial COI genes. The endosymbionts comprised two distinct clades, one associated with tube worms from basaltic vent habitats and the other associated with tube worms from sedimented seep-like environments. Within each symbiont clade, 16S rDNA sequences were nearly identical, suggesting that vent vestimentiferans share a single endosymbiont species that is distinct from the seep endosymbiont species. A third endosymbiont type, related to the seep species, was found in a tube worm collected from a whale carcass. Our results are consistent with a horizontal model of symbiont transmission.
来自深海热液喷口和冷水渗漏处的巨型管虫完全依靠硫氧化细菌内共生体获取营养。我们通过比较共生体16S核糖体DNA和宿主线粒体COI基因的系统发育树，研究了宿主 - 共生体的共同进化。内共生体由两个不同的进化枝组成，一个与来自玄武岩喷口栖息地的管虫相关，另一个与来自沉积的类似渗漏环境的管虫相关。在每个共生体进化枝内，16S rDNA序列几乎相同，这表明喷口巨型管虫共享一个与渗漏内共生体物种不同的单一内共生体物种。在从鲸尸收集的一只管虫中发现了与渗漏物种相关的第三种内共生体类型。我们的结果与共生体传播的水平模型一致。
