Mechanisms of Color Vision: Genomics, Physiology and Behavior

据推测，地球上有100多万种动物使用色觉来寻找食物，寻找配偶和避免被捕食者吃掉。这是因为颜色信息比其他类型的视觉线索（如物体的亮度）更可靠。 尽管动物广泛使用颜色来向潜在的配偶做广告，并警告捕食者免受攻击，但科学家们对大多数生物的色觉工作方式知之甚少，包括为什么某些物种的雄性和雌性之间的色觉不同。 该项目旨在研究一组有毒蝴蝶的视力，这些蝴蝶在翅膀上显示出一种新的颜色，紫外线黄色，并且在眼睛中具有新颖的紫色和紫外线感光器。该项目将确定其基因组的关键部分，这些部分控制眼睛发育和眼睛中感光器的位置，这在性别之间是不同的。 将使用行为测试研究雄性和雌性之间检测颜色的能力差异，并将其与蝴蝶光环境中有助于其生存和繁殖的线索联系起来。此外，该项目还将培养下一代学者-生理学方法的研究生和博士后学生，这将允许记录动物对光的反应。本科生将接受基因组注释方面的培训。最后，该项目将免费提供一种增加难以研究的光敏蛋白质产量的方法，这可能对各种生物技术应用有用。模仿动物的颜色在捕食者混淆的背景下进化。除非拟态动物有区分拟态颜色的适应能力，否则动物本身就有混淆的风险，对交配和繁殖产生负面影响。Heliconius蝴蝶之所以令人感兴趣，是因为许多令人讨厌的物种在新热带地区形成了模仿环。研究小组发现，Heliconius眼睛表达复制的紫外线（UV）视蛋白，并表明这种复制可能是通过增强UV色觉来适应物种识别。拟议的项目将允许通过使用免疫组织化学，字符映射和祖先状态重建追踪感光体进化的物种和性别特异性模式来阐明紫外线视蛋白复制的生物学意义。此外，该项目将利用Heliconius蝴蝶参考基因组以及该项目将产生的其他基因组资源和转录组资源，以确定可能是这些不同谱系中选择目标的眼睛基因沿着重复的UV视蛋白基因。这项工作将以前所未有的细节揭示一组密切相关的蝴蝶在日常生活中遇到的信号中的色觉进化。虽然已经有很多关于信号中的性二态性的工作，但几乎没有关于感觉系统中的性二态性的工作，特别是在色觉中。这是一个主要的空白，我们现在可以开始使用各种方法来填补：Pac-Bio和Illumina DNA测序，ATAC-seq，RNA-seq，细胞内电生理学，细胞培养和行为测试。

More than a million animals on the planet are presumed to use color vision to find food, to find mates and to avoid being eaten by predators. This is because color information is more reliable than other kinds of visual cues like an object's brightness. Despite the widespread use of color by animals to advertise to potential mates and to warn predators against attack, scientists know very little about the way color vision works in most organisms, including why color vision differs between males and females in some species. This project aims to examine vision in a group of toxic butterflies that display a new form of coloration on their wings, ultraviolet-yellow, and have novel violet and ultraviolet photoreceptors in their eyes. This project will identify key parts of their genome which control eye development and the placement of photoreceptors in their eyes, which differ between the sexes. The differences in ability between males and females to detect color will be studied using behavioral tests and linked to cues in the butterflies' light environment which contribute to their survival and reproduction. In addition, this project will result in the training of the next generation of scholars - graduate and postdoctoral students in physiological methods, which will permit the recording of an animal's response to light. Undergraduates will be trained in the annotation of genomes. Lastly, the project will make freely-available a method for increasing the production of difficult-to-study light-sensitive proteins, which may be useful for a variety of biotechnology applications. Mimetic animal coloration evolves in the context of predator confusion. Unless mimetic animals have adaptations for discriminating between mimetic colors there is a risk of confusion for the animals themselves, with negative consequences for mating and reproduction. Heliconius butterflies are of interest because many unpalatable species have formed mimicry rings in the Neotropics. The research team has discovered that Heliconius eyes express duplicated ultraviolet (UV) opsins and have shown that this duplication may be an adaptation for species recognition, via enhanced UV color vision. The proposed project will permit the elucidation of the biological significance of the ultraviolet opsin duplication by tracing species- and sex-specific patterns of photoreceptor evolution using immunohistochemistry, character mapping, and ancestral state reconstruction. In addition the project will draw on a Heliconius butterfly reference genome together with other genomic resources and transcriptomic resources that the project will generate, to identify eye genes that may have been the target of selection in these different lineages along with the duplicate UV opsin gene. The proposed work will reveal in unprecedented detail the evolution of color vision within a group of closely-related butterflies in relation to the signals they encounter in their daily lives. Whereas there has been much work on sexual dimorphism in signals, there is virtually no work on sexual dimorphism in sensory systems especially in color vision. This is a major gap that we can now begin to fill using a variety of methods: Pac-Bio and Illumina DNA-sequencing, ATAC-seq, RNA-seq, intracellular electrophysiology, cell culture, and behavioral tests.