Goffredi Shana K, Warén Anders, Orphan Victoria J, Van Dover Cindy L, Vrijenhoek Robert C
Monterey Bay Aquarium Research Institute, Moss Landing, California 95039, USA.
Appl Environ Microbiol. 2004 May;70(5):3082-90. doi: 10.1128/AEM.70.5.3082-3090.2004.
Here we describe novel forms of structural integration between endo- and episymbiotic microbes and an unusual new species of snail from hydrothermal vents in the Indian Ocean. The snail houses a dense population of gamma-proteobacteria within the cells of its greatly enlarged esophageal gland. This tissue setting differs from that of all other vent mollusks, which harbor sulfur-oxidizing endosymbionts in their gills. The significantly reduced digestive tract, the isotopic signatures of the snail tissues, and the presence of internal bacteria suggest a dependence on chemoautotrophy for nutrition. Most notably, this snail is unique in having a dense coat of mineralized scales covering the sides of its foot, a feature seen in no other living metazoan. The scales are coated with iron sulfides (pyrite and greigite) and heavily colonized by epsilon- and delta-proteobacteria, likely participating in mineralization of the sclerites. This novel metazoan-microbial collaboration illustrates the great potential of organismal adaptation in chemically and physically challenging deep-sea environments.
在此，我们描述了内共生和外共生微生物之间结构整合的新形式，以及一种来自印度洋热液喷口的不寻常的新蜗牛物种。这种蜗牛在其大大扩大的食管腺细胞内聚居着大量γ-变形菌。这种组织环境与所有其他的喷口软体动物不同，其他喷口软体动物在鳃中含有硫氧化内共生体。显著缩短的消化道、蜗牛组织的同位素特征以及体内细菌的存在表明其营养依赖于化学自养。最值得注意的是，这种蜗牛独特之处在于其足部两侧覆盖着一层致密的矿化鳞片，这一特征在其他现存后生动物中未见。这些鳞片覆盖着硫化铁（黄铁矿和硫复铁矿），并大量聚居着ε-和δ-变形菌，可能参与了硬片的矿化过程。这种新的后生动物与微生物的合作说明了在化学和物理条件具有挑战性的深海环境中生物适应的巨大潜力。
