Expression of opsins, ultrastructure of eyes, and light-induced behaviour in tardigrades (water bears): Insights into the evolution of visual systems and photoreception in panarthropods

缓步动物（水熊）的视蛋白表达、眼睛超微结构和光诱导行为：深入了解泛节肢动物视觉系统和感光的进化

基本信息

批准号：
322918072
负责人：
Professor Dr. Georg Mayer
金额：
--
依托单位：
Fachgebiet Zoologie
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2016
资助国家：
德国
起止时间：
2015-12-31 至 2020-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/322918072?language=en
关键词：
Expression opsins ultrastructure eyes light

项目摘要

The ability to perceive light is widely distributed among animals, but the evolution of this complex sensory capacity is not fully understood. One particular gap in our knowledge concerns the visual system of tardigrades (water bears). Despite their key phylogenetic position as one of the closest arthropod relatives, insufficient data are available on the ultrastructure of the photoreceptors and visual organs of tardigrades. Moreover, data on the expression of opsin genes, which have been identified recently in a tardigrade species, are completely missing, although these proteins play a key role in light reception and light-induced behaviour. The major goal of the planned project is therefore: (i) to analyse the ultrastructure of photoreceptors and to perform a 3D reconstruction of eyes in representatives of two major tardigrade subgroups, the Heterotardigrada and Eutardigrada, as these data will provide essential information on visual properties of the tardigrade eye; (ii) to immunolocalise all opsin proteins known from tardigrades in order to clarify which of these proteins are involved in vision and which ones are non-visual molecules; and (iii) to study the phototactic/photokinetic behaviour in the tardigrade Hypsibius dujardini and to examine the spectral sensitivity of this species to clarify to which wavelengths of light it responds. The new data will help us to understand the visual and photosensory system of tardigrades and to shed light on its evolution since the divergence of the three major panarthropod groups: Arthropoda, Onychophora, and Tardigrada.

感知光的能力在动物中广泛分布，但这种复杂的感觉能力的进化尚不完全清楚。我们知识中的一个特殊空白涉及缓步动物（水熊虫）的视觉系统。尽管它们作为最接近的节肢动物亲戚之一具有重要的系统发育地位，但关于缓步动物的光感受器和视觉器官的超微结构的数据不足。此外，最近在缓步动物中发现的视蛋白基因表达的数据完全缺失，尽管这些蛋白质在光接收和光诱导行为中发挥着关键作用。因此，计划项目的主要目标是：（i）分析光感受器的超微结构，并对两个主要缓步动物亚群（Heterotardigrada 和 Eutardigrada）的代表的眼睛进行 3D 重建，因为这些数据将提供有关视觉特性的重要信息缓步动物的眼睛； (ii) 对缓步动物已知的所有视蛋白进行免疫定位，以澄清这些蛋白中哪些与视觉有关，哪些是非视觉分子； (iii) 研究缓步动物 Hypsibius dujardini 的趋光/光动行为，并检查该物种的光谱敏感性，以阐明其对哪些波长的光作出反应。新数据将帮助我们了解缓步动物的视觉和光感觉系统，并揭示自节肢动物门、有甲动物和缓步动物这三个主要泛节肢动物类群分化以来缓步动物的进化。