The evolution of opsin genes in five species of mirid bugs: duplication of long-wavelength opsins and loss of blue-sensitive opsins

作者：Pengjun Xu, Bin Lu, Jiangtao Chao, Robert Holdbrook, Gemei Liang, Yanhui Lu · 发表于：BMC Ecology and Evolution · 年份：2021 · DOI：10.1186/s12862-021-01799-5 · 被引用次数：20 · 研究领域：Neurobiology and Insect Physiology Research、Animal Behavior and Reproduction、Retinal Development and Disorders

BACKGROUND: Color vision and phototactic behavior based on opsins are important for the fitness of insects because of their roles in foraging and mate choice. Related topics, including the duplication and loss of opsin genes, have been well investigated in insect orders such as Coleoptera, Lepidoptera, Hymenoptera, Odonata and Orthoptera, and the findings have been used to develop pest management strategies involving light trapping. Mirid bugs of Hemiptera, which are pests that cause heavy economic losses, show capacity for color discrimination and phototaxis. However, the opsins in mirid bugs remain uncharacterized. Herein, we examined five species to investigate the evolution of opsins in the family Miridae. RESULTS: Using RNA-seq, we identified several contigs showing high identity with opsins, including four contigs in Apolygus lucorum and three contigs each in Adelphocoris suturalis, Adelphocoris fasciaticollis, Adelphocoris lineolatus and Nesidiocoris tenuis. Phylogenetic analyses indicated that one of these genes clustered with ultraviolet-sensitive (UV) opsins and that the others clustered with long-wavelength (LW) opsins, suggesting that duplication of LW opsins and loss of blue light-sensitive (B) opsins occurred in mirid bugs. The existence of introns in the LW opsins of mirid bugs suggested that the duplication events were DNA based. Both LW1 and LW2 opsins of mirid bugs were found to be under strong purifying selection. The LW1 opsins were significantly more high...