Swafford Andrew J M, Oakley Todd H
Ecology, Evolution, and Marine Biology, University of California Santa Barbara, Santa Barbara, CA 93106, USA.
Ecology, Evolution, and Marine Biology, University of California Santa Barbara, Santa Barbara, CA 93106, USA
J Exp Biol. 2018 Jan 19;221(Pt 2):jeb163196. doi: 10.1242/jeb.163196.
Complex sensory systems often underlie critical behaviors, including avoiding predators and locating prey, mates and shelter. Multisensory systems that control motor behavior even appear in unicellular eukaryotes, such as , which are important laboratory models for sensory biology. However, we know of no unicellular opisthokonts that control motor behavior using a multimodal sensory system. Therefore, existing single-celled models for multimodal sensorimotor integration are very distantly related to animals. Here, we describe a multisensory system that controls the motor function of unicellular fungal zoospores. We found that zoospores of exhibit both phototaxis and chemotaxis. Furthermore, we report that closely related species respond to either the chemical or the light stimuli presented in this study, not both, and likely do not share this multisensory system. This diversity of sensory systems within provides a rare example of a comparative framework that can be used to examine the evolution of sensory systems following the gain/loss of available sensory modalities. The tractability of and related fungi as laboratory organisms will facilitate detailed mechanistic investigations into the genetic underpinnings of novel photosensory systems, and how multisensory systems may have functioned in early opisthokonts before multicellularity allowed for the evolution of specialized cell types.
复杂的感觉系统通常是关键行为的基础，包括躲避捕食者以及定位猎物、配偶和庇护所。控制运动行为的多感觉系统甚至出现在单细胞真核生物中，比如 ，它们是感觉生物学重要的实验室模型。然而，我们所知的单细胞后鞭毛生物中没有利用多模态感觉系统来控制运动行为的。因此，现有的用于多模态感觉运动整合的单细胞模型与动物的亲缘关系非常远。在这里，我们描述了一种控制单细胞真菌游动孢子运动功能的多感觉系统。我们发现 的游动孢子表现出趋光性和趋化性。此外，我们报告说，密切相关的 物种只对本研究中呈现的化学或光刺激作出反应，而非两者都有反应，并且可能不具备这种多感觉系统。 内感觉系统的这种多样性提供了一个罕见的比较框架示例，可用于研究在可用感觉模态获得/丧失后感觉系统的进化。 以及相关真菌作为实验室生物的易处理性将有助于对新型光感觉系统的遗传基础以及在多细胞性允许特化细胞类型进化之前多感觉系统在早期后鞭毛生物中可能如何发挥作用进行详细的机制研究。
