Extracellular bacterial association in gills of «wood mussels»
Extracellular bacterial association in gills of «wood mussels»
复制标题
«木贻贝» 鳃中的细胞外细菌关联
作者：
O. Gros;F. Gaill
四种“形态类型”的贻贝科是从西太平洋（瓦努阿图群岛）和保和海（菲律宾）300 至 1800 米深度之间的木瀑布中收集到的。我们的研究结果表明，在所分析的四种贻贝形态类型中，沿着鳃丝侧向区域的细胞顶端表面的微绒毛之间存在细胞外细菌。根据 TEM 观察，这些革兰氏阴性细菌由于其细胞质中缺乏同心堆积的细胞内膜，因此不具有甲烷氧化能力。根据 FISH 实验，这些细菌属于 γ-Proteobacteria。这些初步观察描述了与沉没木材相关的后生动物物种中类似鳃共生的相互作用，加强了这样的假设：分解木材可能是共生贻贝科引入通风口和渗漏的步骤。我们的实验室正在进行这些胞外细菌的系统发育分析，以便将它们的 16SrDNA 序列与迄今为止描述的其他海洋无脊椎动物共生体的序列进行比较。
Four «morphotypes» of Mytilidae were collected from wood falls in the west Pacific (Vanuatu islands) and in the Bohol sea (Philippines) between 300 and 1800 metre depth. Results from our study demonstrated the existence of extra- cellular bacteria located between microvilli at the apical surface of the cells all along the lateral zone of the gill filaments in the four mytilid morphotypes analyzed. Based on TEM observations, these Gram-negative bacteria were not methano- trophic due to the lack of concentric stacking of intracellular membranes in their cytoplasm. Based on FISH experiments, these bacteria belong to γ-Proteobacteria. These preliminary observations described gill symbiosis-like interactions in metazoan species associated with sunken wood, strengthening the hypothesis that decomposing wood may serve as steps for the introduction of symbiotic Mytilidae to vents and seeps. Phylogenetic analysis of these extracellular bacteria are in progress in our lab in order to compare their 16SrDNA sequences to that of other marine invertebrate symbionts described to date.