PDF(Pubmed)
Abstract：
Opsins are a class of transmembrane proteins encoded by opsin genes, and they play a variety of functional roles. Short wavelength-sensitive opsin 2 (sws2), one of the five classes of visual opsin genes, mainly senses blue light. Previous research has indicated that sws2 is essential for melanocyte formation in fish; however, its specific role in skin color differentiation remains to be elucidated. Here, we identified the sws2 gene in a prized reef-dwelling fish, Plectropomus leopardus. The full-length P. leopardus sws2 gene encodes a protein consisting of 351 amino acids, and exhibits substantial homology with other fish species. The expression of the sws2 gene was widespread across P. leopardus tissues, with high expression in eye and skin tissues. Through immunohistochemistry and in situ hybridization analyses, we discovered that the sws2 gene was primarily localized in the rod and cone cells of the retina, and epidermal cells of the skin. Furthermore, dsRNA interference was used for sws2 gene knockdown in living P. leopardus to elucidate its function in skin color differentiation. Black-color-related genes, melanin contents, and tyrosinase activity in the skin significantly decreased after sws2 knockdown (p < 0.05), but red-color-related genes and carotenoid and lutein contents significantly increased (p < 0.05). Retinoic acid injection produced the opposite results. Our results suggested that the sws2 gene influences P. leopardus skin color regulation by affecting vitamin synthesis and melanin-related gene expression levels. This study establishes a foundation for elucidating the molecular mechanisms by which sws2 regulates melanocyte formation in fish skin.
摘要：
视蛋白是一类由视蛋白基因编码的跨膜蛋白，他们扮演各种功能角色。短波长敏感视蛋白2（sws2），视觉视蛋白基因的五类之一，主要感知蓝光。先前的研究表明，sws2对于鱼类的黑素细胞形成至关重要；然而，其在肤色分化中的具体作用还有待阐明。这里,我们在一种珍贵的珊瑚礁栖息鱼类中发现了sws2基因，白质多形虫。全长P.leopardussws2基因编码由351个氨基酸组成的蛋白质，并表现出与其他鱼类的实质性同源性。sws2基因的表达广泛存在于黑质假单胞菌组织中，在眼睛和皮肤组织中具有高表达。通过免疫组织化学和原位杂交分析，我们发现sws2基因主要位于视网膜的视杆和视锥细胞中，和皮肤的表皮细胞。此外，将dsRNA干扰用于活黄斑鱼的sws2基因敲除，以阐明其在皮肤颜色分化中的功能。与黑色相关的基因，黑色素含量,SWS2敲低后，皮肤中的酪氨酸酶活性显着降低（p<0.05），但红色相关基因、类胡萝卜素和叶黄素含量显著增加(p<0.05)。视黄酸注射产生相反的结果。我们的结果表明，sws2基因通过影响维生素合成和黑色素相关基因表达水平来影响白羊座皮肤颜色调节。本研究为阐明sws2调节鱼皮黑素细胞形成的分子机制奠定了基础。
