Differentially-expressed opsin genes identified in Sinocyclocheilus cavefish endemic to China

• Published in: Current zoology 2013-04, Vol.59 (2), p.170-174
• Main Authors: Meng, Fanwei, Zhao, Yahui, Postlethwait, John H, Zhang, Chunguang
• Format: Article
• Language: English
• Subjects: 中国; 分子生物学; 基因差异表达; 洞穴; 表面物种; 视蛋白; 金线鲃属; 鱼类学
• ISSN: 1674-5507; 2396-9814
• DOI: 10.1093/czoolo/59.2.170

Eye degeneration is a common troglomorphic character of cave-dwelling organisms. Comparing the morphology and molecular biology of cave species and their close surface relatives is a powerful tool for studying regressive eye evolution and other adaptive phenotypes. We compared two co-occurring and closely-related species of the fish genus Sinocyclocheilus, which is endemic to China and includes both surface- and cave-dwelling species. Sinocyclocheilus tileihornes, a cave species, had smaller eyes than Sinocyclocheilus angustiporus, a surface species. Histological and immunohistochemical analyses revealed that the cave- fish had shorter cones and more disorderly rods than did the surface-dwelling species. Using quantitative PCR and in situ hybri- dization, we found that rhodopsin and a long-wavelength sensitive opsin had significantly lower expression levels in the cavefish. Furthermore, one of two short-wavelength-sensitive opsins was expressed at significantly higher levels in the cavefish. Changes in the expression ofopsin genes may have played a role in the degeneration of cavefish eyes [Current Zoology 59 （2）： 170-174, 2013].