Spectral shifts of mammalian ultraviolet-sensitive pigments (short wavelengthsensitive opsin 1) are associated with eye length and photic niche evolution
Spectral shifts of mammalian ultraviolet-sensitive pigments (short wavelengthsensitive opsin 1) are associated with eye length and photic niche evolution
复制标题
DOI：
10.1098/rspb.2015.1817
复制
发表时间：
2015-11-22
影响因子：
4.7
通讯作者：
Springer, Mark S.
中科院分区：
文献类型：
--
作者：
Emerling, Christopher A.;Huynh, Hieu T.;Springer, Mark S.
当受到光刺激时，视网膜视蛋白色素启动哺乳动物的视觉。大多数哺乳动物都拥有一种短波长敏感的视蛋白1（SWS 1）色素，主要对紫外线或紫光敏感，导致物种间的颜色感知差异。尽管知识的紫外线和紫色敏感的SWS 1类哺乳动物25年，这种变化的适应意义还没有进行假设检验，导致最小的理解哺乳动物SWS 1光谱调谐进化的基础。在这里，我们收集了403种哺乳动物的SWS 1数据，包括97种哺乳动物的新SWS 1序列。祖先序列重建表明，最近的共同祖先兽拥有紫外线SWS 1色素，和紫色敏感的色素进化至少12次在哺乳动物的历史。我们还观察到，以前被认为是罕见的紫外线色素在哺乳动物中很常见。然后，我们使用系统发育比较的方法来测试的假设，紫色敏感SWS 1的进化与增加曝光，延长寿命和更长的眼睛长度。我们发现，白天活动的哺乳动物和眼睛较长的物种更有可能拥有对紫色敏感的色素，而不太可能拥有对紫外线敏感的色素。我们假设：（i）随着哺乳动物进化出更大的体型，它们进化出更长的眼睛，由于瑞利散射的增加，这限制了紫外线对视网膜的透射率，以及（ii）随着哺乳动物开始侵入昼夜时间小生境，它们进化出具有低紫外线透射率的晶状体，以减少色差和/或光氧化损伤。
Retinal opsin photopigments initiate mammalian vision when stimulated by light. Most mammals possess a short wavelength-sensitive opsin 1 (SWS1) pigment that is primarily sensitive to either ultraviolet or violet light, leading to variation in colour perception across species. Despite knowledge of both ultra-violet-and violet-sensitive SWS1 classes in mammals for 25 years, the adaptive significance of this variation has not been subjected to hypothesis testing, resulting in minimal understanding of the basis for mammalian SWS1 spectral tuning evolution. Here, we gathered data on SWS1 for 403 mammal species, including novel SWS1 sequences for 97 species. Ancestral sequence reconstructions suggest that the most recent common ancestor of Theria possessed an ultraviolet SWS1 pigment, and that violet-sensitive pigments evolved at least 12 times in mammalian history. We also observed that ultraviolet pigments, previously considered to be a rarity, are common in mammals. We then used phylogenetic comparative methods to test the hypotheses that the evolution of violet-sensitive SWS1 is associated with increased light exposure, extended longevity and longer eye length. We discovered that diurnal mammals and species with longer eyes are more likely to have violet-sensitive pigments and less likely to possess UV-sensitive pigments. We hypothesize that (i) as mammals evolved larger body sizes, they evolved longer eyes, which limited transmittance of ultraviolet light to the retina due to an increase in Rayleigh scattering, and (ii) as mammals began to invade diurnal temporal niches, they evolved lenses with low UV transmittance to reduce chromatic aberration and/or photo-oxidative damage.