Kasagi Satoshi, Mizusawa Kanta, Murakami Naoto, Andoh Tadashi, Furufuji Sumihisa, Kawamura Shoji, Takahashi Akiyoshi
School of Marine Biosciences, Kitasato University, Kitasato, Minami-ku, Sagamihara, Kanagawa 252-0373, Japan.
School of Marine Biosciences, Kitasato University, Kitasato, Minami-ku, Sagamihara, Kanagawa 252-0373, Japan.
Gene. 2015 Feb 10;556(2):182-91. doi: 10.1016/j.gene.2014.11.054. Epub 2014 Nov 26.
Green light irradiation facilitates the somatic growth of barfin flounder (Verasper moseri). However, the V. moseri visual system, which may be associated with somatic growth by acting on the endocrine system upon exposure to this particular wavelength, remains largely unexplored. Herein, we characterized the visual opsin repertoire of V. moseri to understand the molecular basis underlying this effect. The five types of visual opsins that are found in vertebrates were cloned from RNA that was extracted from the eyes of V. moseri. Notably, V. moseri possessed one pseudogene (RH2-A) and two intact (RH2-B and RH2-C) copies of "green-sensitive" opsin genes. The wavelengths of maximum absorption spectra (λmax) for each of the reconstituted photopigments were 552nm for "red-sensitive" LWS, 506nm for RH2-B, 490nm for RH2-C, 482nm and 416nm for "blue-sensitive" SWS2A and SWS2B, respectively, 367nm for "ultraviolet-sensitive" SWS1, and 494nm for "dim-light sensitive rhodopsin" RH1. The λmax of SWS2A was longer than that of any other reported vertebrate SWS2 opsin. By measuring the expression level of these opsin genes with quantitative RT-PCR in 3-, 15-, and 27-month-old fish, we found that RH2-B and SWS2A were expressed at a constant level, whereas the expression of LWS, RH2-C, SWS2B, and SWS1 opsin genes decreased, and that of RH1 increased with age. Barfin flounders inhabit inshore waters at a young age and expand their habitat to deep sea areas as they age, and green light is relatively abundant in deep water compared to the lights of other wavelengths in shallow water. Our results indicate that gene repertoire and expression profile of the opsin genes of barfin flounder are adaptive to their habitat shift that occurs during development, with some opsins acquiring a distinct λmax.
绿光照射促进条石鲷(Verasper moseri)的体细胞生长。然而,条石鲷的视觉系统在暴露于这种特定波长时可能通过作用于内分泌系统而与体细胞生长相关,但在很大程度上仍未得到探索。在此,我们对条石鲷的视觉视蛋白种类进行了表征,以了解这种效应背后的分子基础。从条石鲷眼睛提取的RNA中克隆出了脊椎动物中发现的五种视觉视蛋白。值得注意的是,条石鲷拥有一个假基因(RH2-A)和两个完整的(RH2-B和RH2-C)“绿色敏感”视蛋白基因拷贝。每种重组光色素的最大吸收光谱波长(λmax)分别为:“红色敏感”的LWS为552nm,RH2-B为506nm,RH2-C为490nm,“蓝色敏感”的SWS2A和SWS2B分别为482nm和416nm,“紫外线敏感”的SWS1为367nm,“暗光敏感视紫红质”RH1为494nm。SWS2A的λmax比任何其他已报道的脊椎动物SWS2视蛋白都长。通过定量RT-PCR测量3个月、15个月和27个月大的鱼中这些视蛋白基因的表达水平,我们发现RH2-B和SWS2A以恒定水平表达,而LWS、RH2-C、SWS2B和SWS1视蛋白基因的表达随年龄下降,RH1的表达随年龄增加。条石鲷幼鱼栖息在近岸水域,随着年龄增长其栖息地扩展到深海区域,与浅水中其他波长的光相比,绿光在深水中相对丰富。我们的结果表明,条石鲷视蛋白基因的种类和表达谱适应其发育过程中发生的栖息地转移,一些视蛋白获得了独特的λmax。