Many animals including birds, reptiles, insects, and teleost fishes can see ultraviolet (UV) light (shorter than 400 nm), which has functional importance for foraging and communication. For coral reef fishes, shallow reef environments transmit a broad spectrum of light, rich in UV, driving the evolution of diverse spectral sensitivities. However, the identities and sites of the specific visual genes that underly vision in reef fishes remain elusive and are useful in determining how evolution has tuned vision to suit life on the reef. We investigated the visual systems of 11 anemonefish (Amphiprioninae) species, specifically probing for the molecular pathways that facilitate UV-sensitivity. Searching the genomes of anemonefishes, we identified a total of eight functional opsin genes from all five vertebrate visual opsin subfamilies. We found rare instances of teleost UV-sensitive SWS1 opsin gene duplications that produced two functionally coding paralogs (SWS1α and SWS1β) and a pseudogene. We also found separate green sensitive RH2A opsin gene duplicates not yet reported in the family Pomacentridae. Transcriptome analysis revealed false clown anemonefish (Amphiprion ocellaris) expressed one rod opsin (RH1) and six cone opsins (SWS1β, SWS2B, RH2B, RH2A-1, RH2A-2, LWS) in the retina. Fluorescent in situ hybridization highlighted the (co-)expression of SWS1β with SWS2B in single cones, and either RH2B, RH2A, or RH2A together with LWS in different members of double cone photoreceptors (two single cones fused together). Our study provides the first in-depth characterization of visual opsin genes found in anemonefishes and provides a useful basis for the further study of UV-vision in reef fishes.

中文翻译：

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海葵鱼（Amphiprioninae）中紫外线视觉视蛋白的分子进化和光感受器的光谱调谐

许多动物，包括鸟类、爬行动物、昆虫和硬骨鱼类，都可以看到紫外线 (UV) 光（小于 400 nm），这对于觅食和交流具有重要的功能。对于珊瑚礁鱼类来说，浅礁环境会传输广谱的光，富含紫外线，从而推动了不同光谱灵敏度的演变。然而，构成礁鱼视觉基础的特定视觉基因的身份和位点仍然难以捉摸，并且有助于确定进化如何调整视觉以适应礁石上的生命。我们调查了 11 种海葵鱼 (Amphiprioninae) 的视觉系统，专门探索促进紫外线敏感性的分子途径。搜索 anemonefishes 的基因组，我们从所有五个脊椎动物视觉视蛋白亚科中确定了总共八个功能性视蛋白基因。我们发现了硬骨鱼紫外线敏感的 SWS1 视蛋白基因重复的罕见实例，这些重复产生了两个功能编码旁系同源物（SWS1α 和 SWS1β）和一个假基因。我们还发现了尚未在 Pomacentridae 家族中报道的单独的绿色敏感 RH2A 视蛋白基因重复。转录组分析显示假小丑海葵 (Amphiprion ocellaris) 在视网膜中表达一种视杆视蛋白 (RH1) 和六种视锥蛋白 (SWS1β, SWS2B, RH2B, RH2A-1, RH2A-2, LWS)。荧光原位杂交突出了 SWS1β 与 SWS2B 在单锥体中的（共）表达，以及 RH2B、RH2A 或 RH2A 与 LWS 在双锥体感光器的不同成员（两个单锥体融合在一起）中的（共）表达。