Collaborative Research: The evolution of bioluminescence and light detection in deep-sea shrimp (Oplophoridae and Sergestidae)

生物发光在陆地上是罕见的，在深海中非常常见，80%的动物生活在200米到1000米深的地方。这些动物依靠生物发光进行交流、摄食和/或防御；因此，光的产生和检测对它们的生存至关重要。我们目前对这一现象的了解有限，因为收集活的深海动物很困难，而且缺乏研究这一复杂系统所需的适当技术。然而，现在有了新的基因组技术，一个在深海生物学、视觉和基因组学方面具有丰富经验的团队已经组建起来领导这个项目。这个项目将研究三个问题：1)深海虾不同类型的生物发光的进化模式是什么？2)深海生物的眼睛是如何适应检测生物发光的？3)生物发光器官(称为光团)除了发光之外还能探测到光吗？这项研究的发现将为了解一个对通信、防御、伪装和物种识别至关重要的复杂系统提供有价值的见解。这项研究将为深海和进化生物学领域带来贡献，并立即提高我们对海洋环境中生物发光和光检测的认识。除了科学进步，该项目还将通过开发和传播教育工具、一系列以分子和生物为基础的讲习班、博物馆展品、公共研讨会和生物多样性倡议，接触到幼儿园到大学年龄的学生。这个项目结合了系统基因组学、生理学和分子研究来测试几个假说，这些假说涉及到一个非凡的深海虾家族中生物发光和光检测的进化。Oplophoridae科的所有虾都使用从嘴里排出的发光分泌物来阻止捕食者，而只有一些虾具有第二种生物发光机制，即以光团的形式。发光体是在身体各处发现的发光器官，被认为具有逆光和吸引配偶的功能。这些不同类型的生物发光发出的光的波长和光谱带宽略有不同。过去的研究表明，具有分泌物和光团的虾具有独特的视觉系统来区分这些不同的生物发光类型。然而，结合基因组、分子和生理学方法的深入表征从未被应用于研究这一系统。此外，具有发光体的动物如何能如此精确地匹配向下流动的光照度，这一直是一个谜。新的初步证据表明，光团含有光色素蛋白(Opsins)和其他允许光检测的光转导基因。这是第一个表明自生光器官也可能具有光探测能力的迹象。这增加了一种令人兴奋的可能性，即一些虾可以从眼睛以外的结构中“看到”，并可能为它们独特的逆光能力提供一种机制。第一个目标是使用系统基因组学方法建立一个强大的系统发育图，以追踪叶绿体对虾两种生物发光模式(分泌物和发光体)的进化起源。其次，这个项目将描述深海虾的视觉系统，以更好地了解虾如何区分不同波长的生物发光。最后，将使用综合方法来检测几个非细菌(自生)光器官-光轮和害虫(Sergstidae的光器官)的光敏性。

Bioluminescence, which is rare on land, is extremely common in the deep sea, being found in 80% of the animals living between 200 and 1000 meters depth. These animals rely on bioluminescence for communication, feeding, and/or defense; so, the generation and detection of light is essential to their survival. Our present knowledge of this phenomenon has been limited due to the difficulty in collecting live deep-sea animals, and the lack of proper techniques needed to study this complex system. However, new genomic techniques are now available, and a team with extensive experience in deep-sea biology, vision, and genomics has been assembled to lead this project. This project will study three questions 1) What are the evolutionary patterns of different types of bioluminescence in deep-sea shrimp? 2) How are deep-sea organisms' eyes adapted to detect bioluminescence? 3) Can bioluminescent organs (called photophores) detect light in addition to emitting light? Findings from this study will provide valuable insight into a complex system vital to communication, defense, camouflage, and species recognition. This study will bring contributions to the fields of deep sea and evolutionary biology, and immediately improve our understanding of bioluminescence and light detection in the marine environment. In addition to scientific advancement, this project will reach kindergarten through college aged students through the development and dissemination of educational tools, a series of molecular and organismal-based workshops, museum exhibits, public seminars, and biodiversity initiatives. This project combines phylogenomic, physiological, and molecular studies to test several hypotheses addressing the evolution of bioluminescence and light detection in a remarkable family of deep-sea shrimp. All shrimp within the family Oplophoridae use a luminescent secretion discharged from the mouth to deter predators, while only some possess a second mechanism of bioluminescence in the form of photophores. Photophores are light-emitting organs found across the body that are thought to function in counterillumination and mate attraction. These different types of bioluminescence emit light at slightly different wavelengths and spectral bandwidths. Past studies have shown shrimp with both the secretion and photophores possess unique visual systems to distinguish between these different bioluminescence types. However, an in-depth characterization, which combines genomic, molecular, and physiological methods, has never been applied to investigate this system. In addition, how animals with photophores can so precisely match the downwelling irradiance has remained a long-standing mystery. New preliminary evidence suggests that the photophores contain photopigment proteins (opsins) and other phototransduction genes that allow for light detection. This is the first indication that autogenic light organs may also have light detection capabilities. This raises the exciting possibility that some shrimp can "see" from structures other than their eyes and might provide a mechanism for their unique counterillumination abilities. The first objective is to use phylogenomic methods to build a robust phylogeny to trace the evolutionary origins of the two bioluminescence modes (secretion and photophore) within oplophorid shrimp. Secondly, this project will characterize the visual systems of deep-sea shrimp to better understand how shrimp distinguish between different wavelengths of emitted bioluminescence. Lastly, integrative methods will be used to examine photosensitivity in several non-bacterial (autogenic) light organs - the photophore and organs of Pesta (light organ of Sergestidae).