Adaptive loss of shortwave-sensitive opsins during cartilaginous fish evolution

作者：Bo Zhang, Yidong Feng, Meiqi Lv, Lei Jia, Yongguan Liao, Xiaoyan Xu, Axel Meyer, Jinsheng Sun, Guangyi Fan, Yumin Li, Yumin Li, Yaolei Zhang, Na Zhao, Yunkai Li, Yunkai Li, Baolong Bao · 发表于：Nature Communications · 年份：2025 · DOI：10.1038/s41467-025-62544-w · 被引用次数：7 · 研究领域：Retinal Development and Disorders、Ichthyology and Marine Biology、Fish biology, ecology, and behavior

Cartilaginous fishes (e.g., sharks, rays, and skates) cannot see blue or violet light, potentially because they lack the shortwave-sensitive cone opsin gene (sws). Widespread gene loss can occur during evolution, but the evolutionary mechanisms underlying sws loss remains unclear. Here, we construct whole-genome assemblies of Okamejei kenojei (skate) and Prionace glauca (blue shark). We then analyze the distribution characteristics and intragroup differences of opsin-related genes in cartilaginous fishes. Using a zebrafish model with sws deleted we infer that in the presence of SWS1 and SWS2, blue and violet light respectively, can induce cell aging. This is followed by photoreceptor layer thinning, demonstrating, sws loss aids in preventing shortwave light damage to the eye. In the retinas of numerous cartilaginous fishes, the tapetum lucidum strongly reflects light. Therefore, in cartilaginous fish, the existence of tapetum lucidum in the retina and loss of sws may be interdependent; in other words, this adaptive gene loss may increase cartilaginous fish fitness. Cartilaginous fishes lost the short-wave-sensitive (sws) opsin genes at some point in their evolutionary history. Here, the authors present genome assemblies of Okamejei kenojei (skate) and Prionace glauca (blue shark) that confirm sws loss, together with experimental evidence that sws loss reduces shortwave light damage to the eye.