Evolution of Endosymbiosis in (xylotrophic) Wood-Eating Bivalves

缅因大学（University of Maine）的丹尼尔·l·迪斯特尔（Daniel L. Distel）博士获得了一笔拨款，用于研究蛀木蛤的进化。虽然不为公众所熟知，但蛀木蛤是一种破坏性物种，可以被认为是海洋中的白蚁。它们包括许多不同的物种，每年在全球海洋环境中对木结构、船只和渔具造成超过10亿美元的损失。其中最具破坏性的是“船虫”；像蠕虫一样的蛤，在木头里挖洞并吃木头。这些贪婪的食木动物可以在不到一年的时间里摧毁一个直径12英寸的码头桩。尽管它们看起来像蠕虫，但分子证据表明，它们与普通的“蒸蛤”（一种新英格兰菜肴的主食）密切相关。这项研究的目的是利用来自几个基因的分子数据来揭示木钻蛤与其他更常见的双壳类动物的进化关系，并利用这些数据更好地了解它们的破坏性习惯是如何进化的，包括相关细菌的作用。虽然可以用广谱化学杀菌剂处理木材以控制木材蛀虫的损害，但由于环境问题，最近在许多州和国家限制或禁止使用最有效的处理方法。迫切需要新的无害环境的控制方法，特别是在木材是唯一负担得起的海洋建筑材料的低收入沿海社区。这种控制措施必须专门针对蛀木树种，以尽量减少对生态的影响。进化研究将告诉我们这些令人讨厌的物种是如何发展出破坏木材的能力的，以及它们与其他更受欢迎、经济上更重要的海洋物种的不同之处。这方面的知识对于开发安全且对这些破坏性生物具有高度特异性的控制方法至关重要。

A grant has been awarded to Dr. Daniel L. Distel of the University of Maine to investigate the evolution of wood-boring clams. Though not well known to the general public, wood-boring clams are destructive species that may be considered the marine equivalent of termites. They include many diverse species that cause more than a billion dollars in damage to wooden structures, boats, and fishing gear annually in marine environments worldwide. The most destructive of these are the "shipworms"; worm-like clams that burrow into and eat wood. These voracious wood eaters can destroy a twelve-inch diameter pier piling in less than one year's time. Though they look like worms, molecular evidence suggests that they are closely related to the common "steamer clam", a staple of New England cuisine. The purpose of this investigation is to use molecular data from several genes to reveal the evolutionary relationships of wood boring clams to other more common bivalves and to use these data to better understand how their destructive habits have evolved, including the role of associated bacteria. Although wood can be treated with broad-spectrum chemical biocides to control wood-borer damage, use of the most effective treatments has recently been restricted or banned in many states and nations due to environmental concerns. New environmentally sound control methods are critically needed, particularly in low-income coastal communities where wood is the only affordable marine construction material. Such control measures must be targeted specifically to wood-boring species to minimize ecological impact. Evolutionary studies will tell us how these nuisance species developed the ability to destroy wood and what makes them different from other more desirable and economically important marine species. This knowledge will be essential for developing control methods that are safe and highly specific to these destructive organisms.