The eyes have it: genetic, morphological and functional analysis of differences in compound eyes between Drosophila species

眼睛有它：果蝇物种间复眼差异的遗传、形态和功能分析

• 批准号: BB/T000317/2
• 负责人: Alistair McGregor
• 金额: $ 34.73万
• 依托单位: Durham University
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FT000317%2F2
• 关键词: eyes; genetic; morphological; functional; analysis

Vision is one of the major sensory systems that helps animals navigate through the environment. There is great variation among the eyes of animals reflecting evolutionary adaptations in behaviour and habitat. Two major parameters that determine the quality of vision are: 1) How easily can objects be discriminated at different levels of light luminescence (contrast sensitivity) and 2) how far apart do two objects have to be to be detected discriminated (acuity). Contrast sensitivity depends on the amount of light absorbed by the eye's photoreceptors and therefore on the size of the eye and photoreceptor sensitivity. Acuity on the other hand depends on the density of those light-sensitive photoreceptors, for example, the density of rods and cones in the retina of the human eye. The same rules generally apply to the compound eyes of insects, which are made up of smaller eyes, called ommatidia. Larger ommatidia with larger lens diameters to collect photons gives higher contrast sensitivity. However, acuity depends on the density of ommatidia - more ommatidia per eye area gives higher acuity, and therefore there can be a trade off between contrast sensitivity and acuity determined by the size and number of ommatidia. The size of ommatidia and overall eye size varies greatly among insects, but we still know very little about the genes underlying these evolutionary differences, how this changes the development of eyes, and how these changes in eye morphology alter the vision of these animals. We have found that the gene orthodenticle (otd) causes differences in ommatidia diameter and overall eye size between the closely related species Drosophila mauritiana and Drosophila simulans. We now propose to use a range of approaches to understand how otd regulates ommatidia size and how this gene makes larger eyes in D. mauritiana, and the consequences for their vision. We will first further study the role of otd in specification of ommatidia size in the model organism D. melanogaster to learn more about the mechanisms involved. We will then put the D. mauritiana version of otd into a D. simulans genetic background and vice versa, resulting in a D. simulans fly with a D. mauritiana-like eye and the other way around. These flies can then be compared to pure D. simulans and D. mauritiana flies in their regulation of eye development, eye morphology, neuronal activity and their actual vision. The results of these experiments will reveal how natural genetic variation alters eye development to produce eyes with different optics and how this affects the vision of these flies. This will help us to better understand insect vision generally and provide new insights into how the great diversity of insect eyes and the vision of these animals have evolved. In addition, since there are major similarities between invertebrate and vertebrate eye development, including important roles of otd and its homologues, this project could provide new information about eye development more broadly in animals including humans.

视觉是帮助动物在环境中导航的主要感官系统之一。动物的眼睛之间有很大的变化，反映了行为和栖息地的进化适应。确定视觉质量的两个主要参数是：1）在不同级别的光发光（对比灵敏度）和2）必须检测到两个物体的距离（敏锐度）的距离（敏锐性）。对比灵敏度取决于眼睛的光感受器吸收的光量，因此取决于眼睛和感光体灵敏度的大小。另一方面，敏锐度取决于那些光敏感感受器的密度，例如，人眼视网膜中棒和锥的密度。相同的规则通常适用于昆虫的复合眼，这些昆虫是由较小的眼睛组成的，称为玉米片。具有较大透镜直径的较大的蛋白质以收集光子会产生较高的对比度灵敏度。然而，敏锐度取决于胶质膜的密度 - 每个眼睛区域的豆皮菌更多的敏锐度具有更高的敏锐度，因此可以在造影剂灵敏度和敏锐度之间取得权衡，由羊角菌的大小和数量确定。昆虫的大小和整体眼睛的大小和整体眼睛的大小差异很大，但是我们仍然对这些进化差异的基因了解，这如何改变眼睛的发育以及眼睛形态的这些变化如何改变这些动物的视力。我们发现，基因正畸形（OTD）会导致直径的牙齿直径差异，而密切相关的物种果蝇毛鲁蒂亚纳和果蝇simulans之间的眼睛尺寸差异。现在，我们建议使用一系列方法来了解OTD如何调节Ommatidia的大小以及该基因如何在D. Mauritiana中使更大的眼睛以及其视野的后果。我们将首先进一步研究OTD在模型有机体中OTD规范中的作用D. Melanogaster，以了解有关所涉及机制的更多信息。然后，我们将将D. Mauritiana版本的OTD放入D. simulans遗传背景中，反之亦然，导致D. simulans带着D. Mauritiana般的眼睛飞来飞去，相反。然后，可以将这些苍蝇与纯的D. Simulans和D. Mauritiana进行比较，以调节眼睛发育，眼睛形态，神经元活性及其实际视力。这些实验的结果将揭示自然遗传变异如何改变眼睛发育以产生不同光学的眼睛，以及这如何影响这些苍蝇的视力。这将有助于我们更好地理解昆虫视力，并提供有关昆虫眼睛多样性以及这些动物视野如何发展的新见解。此外，由于无脊椎动物和脊椎动物眼发育之间存在主要相似之处，包括OTD及其同源物的重要作用，因此该项目可以在包括人类在内的动物中更广泛地提供有关眼睛发育的新信息。

项目成果

Evolution of compound eye morphology underlies differences in vision between closely related Drosophila species

复眼形态的进化是密切相关的果蝇物种之间视力差异的基础

• DOI: 10.1101/2023.07.16.549164
• 发表时间: 2023
• 作者: Buffry A