Singh Rachit Pratap, Weng Yi-Ming, Sondhi Yash, Plotkin David, Frandsen Paul B, Kawahara Akito Y
McGuire Center for Lepidoptera and Biodiversity, Florida Museum of Natural History, University of Florida, Gainesville, FL, 32611, USA.
Department of Plant and Wildlife Sciences, Brigham Young University, Provo, UT, USA.
Commun Biol. 2024 Dec 19;7(1):1664. doi: 10.1038/s42003-024-07124-2.
Nearly all animals exhibit a preferred period of daily activity (diel-niche), strongly influenced by the light environment. Vision is a sensory system that is strongly adapted to light, and evolutionary transitions to novel light environments can impose strong constraints on eye evolution, color, and motion vision. While the genetic and neural basis of visual adaptation are well-studied in a few model systems, our understanding across the tree of life remains incomplete. Butterflies and moths are an ideal system to investigate the association between gene evolution and diel-niche transitions. While most butterflies are day-flying, hedylid butterflies are unique in being primarily nocturnal, representing an important evolutionary shift from diurnality to nocturnality. We sequenced the first Hedylidae genome and annotated it to understand genomic changes associated with diel niche shifts. Comparing Hedylidae visual genes to those of other diurnal and nocturnal Lepidoptera revealed that visual genes are highly conserved, with no major losses. However, hedylid opsins were more similar to nocturnal moths than their diurnal congeners, suggesting that these opsins convergently evovled to adapt to the nocturnal environment. Evolutionary rate tests (dN/dS) confirmed strong selection on color vision opsins, with some sites being mapped to the functional domain of the blue opsin. Our study provides new insight into the molecular evolutionary adaptations associated with species' changes to new light environments.
几乎所有动物都表现出每日活动的偏好期（昼夜生态位），这受到光照环境的强烈影响。视觉是一种高度适应光线的感觉系统，向新的光照环境的进化转变会对眼睛进化、颜色和运动视觉施加强大的限制。虽然在一些模式系统中对视觉适应的遗传和神经基础进行了充分研究，但我们对整个生命树的理解仍然不完整。蝴蝶和蛾类是研究基因进化与昼夜生态位转变之间关联的理想系统。大多数蝴蝶在白天飞行，而赫氏蛾科蝴蝶则独特地主要在夜间活动，代表了从昼行性到夜行性的重要进化转变。我们对首个赫氏蛾科基因组进行了测序并注释，以了解与昼夜生态位转变相关的基因组变化。将赫氏蛾科的视觉基因与其他昼行性和夜行性鳞翅目的视觉基因进行比较，发现视觉基因高度保守，没有重大损失。然而，赫氏蛾科的视蛋白与夜行性蛾类的视蛋白比与它们的昼行性同类更相似，这表明这些视蛋白通过趋同进化来适应夜间环境。进化速率测试（dN/dS）证实了对颜色视觉视蛋白有强烈选择，一些位点被定位到蓝色视蛋白的功能域。我们的研究为与物种向新光照环境变化相关的分子进化适应提供了新的见解。
