Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden.
Department of Marine Sciences, University of Gothenburg, Gothenburg, Sweden.
PLoS One. 2019 May 2;14(5):e0216294. doi: 10.1371/journal.pone.0216294. eCollection 2019.
Barnacle settlement involves sensing of a variety of exogenous cues. A pair of antennules is the main sensory organ that the cyprid larva uses to explore the surface. Antennules are equipped with a number of setae that have both chemo- and mechanosensing function. The current study explores the repertoire of sensory receptors in Balanus improvisus cyprid antennules with the goal to better understand sensory systems involved in the settling behavior of this species. We carried out transcriptome sequencing of dissected B. improvisus cyprid antennules. The generated transcriptome assembly was used to search for sensory receptors using HMM models. Among potential chemosensory genes, we identified the ionotropic receptors IR25a, IR8a and IR93a, and several divergent IR candidates to be expressed in the cyprid antennules. We found one gustatory-like receptor but no odorant receptors, chemosensory or odorant-binding proteins. Apart from chemosensory receptors, we also identified 13 potential mechanosensory genes represented by several transient receptor potential channels (TRP) subfamilies. Furthermore, we analyzed changes in expression profiles of IRs and TRPs during the B. improvisus settling process. Several of the sensory genes were differentially expressed during the course of larval settlement. This study gives expanded knowledge about the sensory systems present in barnacles, a taxonomic group for which only limited information about receptors is currently available. It furthermore serves as a starting point for more in depth studies of how sensory signaling affects settling behavior in barnacles with implications for preventing biofouling.
藤壶附着涉及对各种外源线索的感知。一对触角是刚孵化的藤壶幼虫用来探索表面的主要感觉器官。触角上装备有许多刚毛，具有化学和机械感觉功能。本研究旨在更好地了解该物种附着行为所涉及的感觉系统，探索了短滨螺刚孵化的藤壶触角的感觉受体库。我们对解剖的短滨螺刚孵化的藤壶触角进行了转录组测序。使用 HMM 模型从生成的转录组组装中搜索感觉受体。在潜在的化学感觉基因中，我们鉴定了离子型受体 IR25a、IR8a 和 IR93a，以及几个分化的 IR 候选基因在刚孵化的藤壶触角中表达。我们发现了一个味觉样受体，但没有气味受体、化学感觉或气味结合蛋白。除了化学感觉受体，我们还鉴定了 13 个潜在的机械感觉基因，由几个瞬时受体电位通道（TRP）亚家族代表。此外，我们分析了 IR 和 TRP 在短滨螺附着过程中的表达谱变化。在幼虫附着过程中，一些感觉基因的表达发生了差异。这项研究扩展了我们对藤壶感觉系统的认识，藤壶是一个目前关于受体信息有限的分类群。它进一步为更深入地研究感觉信号如何影响藤壶的附着行为提供了起点，这对防止生物污垢具有重要意义。
