科学家长期以来一直认为我们世界海洋的海底有限的生物多样性和复杂的生活。毕竟，任何生物体如何在不使用太阳能量的情况下生存？

1977年，研究人员在加拉帕戈斯群岛（GalápagosIslandsCorliss et al. 1979）。一种s opposed to relying on food-webs driven by photosynthetic energy, deep-sea organisms instead depend on chemosynthesis.

化学合成能是由共生细菌产生的，这些细菌转化了从地壳下方释放的化学物质。我们现在知道，化学合成在整个海底都广泛，范围从热液通风口，冷渗漏，有机瀑布，泥土火山和其他深海沉积物不等。至少已经描述了七种不同的深海无脊椎动物类群具有某种形式的化学合成共生，包括双壳类，螃蟹，虾，尤其

深海小管

深海小管belong to the annelid group Siboglinidae and have drawn considerable attention due to their abundance and dominance in deep-sea chemosynthetic environments. More than 200 species of siboglinids have been described within four major groups (Vestimentifera, Monilifera,Osedax和Frenulata）。

作为成年人，大多数小管植物完全缺乏嘴巴，肠道和肛门，仅依靠硫化氧化细菌进行营养和生长。蠕虫将这些细菌托在一个专门的器官中，称为滋养体。管状Lamellibrachia luymesican be found at cold seeps in the Gulf of Mexico where it acts as an ecosystem engineer, creating habitats for other deep-sea species.

Despite broad scientific interest in understanding tubeworms’ adaptations to deep-sea hydrothermal vents and seeps, the lack of genomic resources has hindered research into the genetic underpinnings that allow them to thrive in extreme environments.

基因组测序L. luymesi提供有关宿主微叶共生的见解

在我们最近在BMC生物学（（Li et al. 2019), we report the complete genome sequence of the cold seep-dwellingL. luymesi解决小管素如何与化学自养细菌建立和维持共生的问题。通过使用比较基因组学，转录组和蛋白质组学分析，我们为分子途径和基因提供了证据，这些途径和基因可能是小管植物对极端环境和共生的非凡适应性的基础。

令我们惊讶的是L. luymesi基因组缺少许多重要基因与氨基酸有关acid synthesis. As amino acids are essential for building proteins in most animals, this result indicates that the host tubeworm depends on symbionts for some critical amino acids. In addition to the provisioning of amino acids by symbionts, we have found evidence of a second possible nutritional mode whereby the host directly digests symbionts, as shown by the detection of abundant host-derived digestive enzymes in trophosome tissue.

Tubeworms can thrive in chemosynthetic habitats thanks to specialized hemoglobin molecules that can bind oxygen and sulfide simultaneously from the environment and transfer it to the bacterial symbionts.

Meanwhile, many gene families are expanded in theLamellibrachiagenome, suggesting different or specialized roles for these genes compared to their known roles in other animals. Among our findings, we identified more hemoglobin genes inL. luymesi比大多数其他动物。血红蛋白是一种铁结合蛋白，负责许多动物的循环系统运输氧气。

One of the remarkable adaptations contributing to the ability of tubeworms to thrive in chemosynthetic habitats involves their specialized hemoglobin molecules that can bind oxygen and sulfide simultaneously from the environment and transfer it to the bacterial symbionts. Several gene families typically involved in immune responses show modification, perhaps indicating a role in tolerance to, or acquisition of, bacterial symbionts.

与其他Lophotrochogos相比，在与蠕虫独特的生活史有关的几个基因家族中观察到了修饰，这些基因家族已知在细胞凋亡，细胞增殖和衰老中起重要作用。后者特别有趣，因为与居住在过热的水热通风孔的亲戚相比，冷渗水型管道的生长速率要慢得多。L. luymesican live up to 250 years, making it one of the most long-lived animals in the world.

我们希望Lamellibrachia luymesi在我们的论文中报道的基因组对于未来的研究将很有价值，以寻求适应极端化学合成环境，令人难以置信的多样化的Annelida的演变以及宿主 - 微生物共生的分子基础。