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

生物发光在陆地上很少见，但在深海中却非常普遍，80%生活在200米至1000米深处的动物都有生物发光。这些动物依靠生物发光进行交流、觅食和/或防御；因此，光的产生和探测对它们的生存至关重要。由于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，我们目前对这一现象的了解有限。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拥有丰富经验的团队已经组建起来领导这个项目。本项目将研究三个问题：1)深海虾不同类型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探测生物发光的？3)生物发光器官（称为光团）除了发光外，还能探测光吗？这项研究的发现将为了解对交流、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探测的认识。除了科学进步之外，该项目还将通过开发和传播教育工具、一系列分子和有机体研讨会、博物馆展览、公共研讨会和生物多样性倡议，将幼儿园和大学生带到大学年龄段。该项目结合了系统基因组学、生理学和分子研究，以测试几个关于深海虾的生物发光和光探测进化的假设。所有Oplophoridae家族的虾都使用从口中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，即光载体。光细胞是遍布全身的发光器官，被认为具有反照明和吸引配偶的功能。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，具有分泌和光载体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，分子和生理方法的深入表征从未应用于研究该系统。此外，具有光细胞的动物如何能够如此精确地匹配向下照射的辐射一直是一个谜。新的初步证据表明，光载体含有光色素蛋白（视蛋白）和其他允许光检测的光传导基因。这是首次表明自体光器官也可能具有光探测能力。这提出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“看”东西，这可能为它们独特的抗光能力提供了一种机制。第一个目标是使用系统基因组学方法建立一个健全的系统发育，以追踪两种生物发光模式（分泌和光载体）在对虾中的进化起源。其次，本项目将表征深海虾的视觉系统，以更好地了解虾如何区分不同波长的生物发光。最后，将采用综合方法检测几种非细菌（自生）光器官的光敏性-光载体和Pesta （Sergestidae的光器官）的器官。

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).