School of Marine Biosciences, Kitasato University, Sagamihara, Kanagawa 252-0373, Japan.
School of Marine Biosciences, Kitasato University, Sagamihara, Kanagawa 252-0373, Japan.
Gene. 2021 Jun 30;787:145622. doi: 10.1016/j.gene.2021.145622. Epub 2021 Mar 31.
We clarified the properties of visual opsin genes in the marbled sole (Pseudopleuronectes yokohamae) by cDNA sequencing, quantification of the opsin gene expression from the larval to the juvenile stage, and measurement of the maximum absorption spectra (λ) using photopigment reconstitution. In the marbled sole eye, at least eight visual opsin genes, lws, rh2-a, rh2-b, rh2-c, sws2a, sws2b, sws1, and rh1, were expressed. Quantitative RT-PCR analysis revealed that the expression of opsin genes increased (lws, rh2-c, sws2a, and rh1) or decreased (rh2-a, rh2-b, sws2b, and sws1) from the larval to the juvenile stage. Notably, rh2-a expression was observed only in pre- to mid-metamorphic stage larvae and disappeared after metamorphosis. Thus, pre-metamorphism-specific expression of rh2-a in the marbled sole suggests that its function is restricted to the developmental stage. The reconstituted RH2-A opsin λ was 470 nm, which is typical of acanthopterygian species. These results strongly suggest that mid-wavelength-sensitive rh2-a expression was diminished drastically in the marbled sole, probably resulting in a shift of spectral sensitivity during its metamorphosis from the larval to the juvenile stage.
我们通过 cDNA 测序阐明了大理石舌鳎（Pseudopleuronectes yokohamae）视觉视蛋白基因的特性，从幼虫到幼鱼阶段定量测定了视蛋白基因的表达，并通过光色素重构测量了最大吸收光谱（λ）。在大理石舌鳎的眼中，至少表达了八个视觉视蛋白基因 lws、rh2-a、rh2-b、rh2-c、sws2a、sws2b、sws1 和 rh1。定量 RT-PCR 分析表明，从幼虫到幼鱼阶段，视蛋白基因的表达增加（lws、rh2-c、sws2a 和 rh1）或减少（rh2-a、rh2-b、sws2b 和 sws1）。值得注意的是，rh2-a 的表达仅在前期到中期变态期幼虫中观察到，变态后消失。因此，大理石舌鳎中 rh2-a 的前变态特异性表达表明其功能仅限于发育阶段。重构的 RH2-A 视蛋白 λ 为 470nm，这是典型的棘鳍鱼类物种。这些结果强烈表明，中波敏感的 rh2-a 在大理石舌鳎中表达急剧减少，可能导致其变态过程中从幼虫到幼鱼阶段的光谱敏感性发生转变。
