Bertinetti César, Meyer Axel, Torres-Dowdall Julián
Zoology and Evolutionary Biology, Department of Biology, University of Konstanz, Constance, Germany.
Department of Biological Sciences, University of Notre Dame, Notre Dame, IN USA.
Hydrobiologia. 2025;852(15):3831-3845. doi: 10.1007/s10750-024-05660-w. Epub 2024 Aug 2.
The wide-ranging photic conditions found across aquatic habitats may act as selective pressures that potentially drive the rapid evolution and diversity of the visual system in teleost fish. Teleost fish fine-tune their visual sensitivities by regulating the two components of visual pigments, the opsin protein and the chromophore. Compared with opsin protein variation, chromophore usage across photic habitats has received little attention. The Nicaraguan Midas cichlid species complex, cf [Günther 1864], has independently colonized seven isolated crater lakes with different photic conditions, resulting in several recent adaptive radiations. Here, we investigate variation in , the main enzyme modulating chromophore exchange. We measured expression in photic environments in the wild, its genetic component in laboratory-reared fish, and its response to different light conditions during development. We found that photic environments significantly predict variation in expression in wild populations and that this variation seems to be genetically assimilated in two populations. Furthermore, light-induced expression exhibited genotype-by-environment interactions in our manipulative experiments. Overall, within-lake variation in expression was higher and inversely related to variation in opsin gene expression along the photic gradient, emphasizing the key role of in the visual ecology of cichlid fish.
The online version contains supplementary material available at 10.1007/s10750-024-05660-w.
在水生栖息地中发现的广泛的光照条件可能作为选择性压力，潜在地推动硬骨鱼视觉系统的快速进化和多样性。硬骨鱼通过调节视觉色素的两个组成部分，即视蛋白和发色团，来微调它们的视觉敏感性。与视蛋白的变异相比，发色团在不同光照栖息地的使用情况很少受到关注。尼加拉瓜的迈达斯丽鱼物种复合体（cf [冈瑟，1864年]）已经独立地在七个具有不同光照条件的孤立火山口湖中定殖，导致了最近的几次适应性辐射。在这里，我们研究了调节发色团交换的主要酶——的变异情况。我们测量了野生环境中光照条件下的表达情况、实验室饲养鱼中的遗传成分以及发育过程中对不同光照条件的反应。我们发现光照环境显著预测了野生种群中表达的变异，并且这种变异似乎在两个种群中发生了遗传同化。此外，在我们的操纵实验中，光诱导的表达表现出基因型与环境的相互作用。总体而言，湖内表达的变异更高，并且与视蛋白基因在光照梯度上的表达变异呈负相关，强调了在丽鱼视觉生态学中的关键作用。
在线版本包含可在10.1007/s10750-024-05660-w获取的补充材料。
