Avian visual pigments: Characteristics, spectral tuning, and evolution
Avian visual pigments: Characteristics, spectral tuning, and evolution
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DOI：
10.1086/510141
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发表时间：
2007-01-01
影响因子：
2.9
通讯作者：
Hunt, David M.
中科院分区：
文献类型：
--
作者：
Hart, Nathan S.;Hunt, David M.
鸟类是高度视觉的动物，具有复杂的视觉系统。在本文中，我们讨论了鸟类视觉色素光谱调谐的光谱特征和遗传机制。鸟类的视网膜含有单一类型的视杆，四种光谱不同类型的单视锥，以及一种单一类型的双视锥感光器。只有单视锥被认为参与了颜色辨别；双视锥被认为参与了非彩色视觉任务，如运动检测和模式识别。鸟类的视色素视蛋白基因与其他脊椎动物的视色素视蛋白基因同源，在脊椎动物进化的早期具有共同的起源。不同种类的鸟类视锥视觉色素的光谱调谐机制在大多数情况下与其他脊椎动物的相似之处。除了紫外线/紫罗兰色(SWS1)类色素；系统发育证据表明，祖先脊椎动物的SWSi色素是紫外线敏感型(UVS)，不同脊椎动物类产生紫敏性(VS)色素的分子机制不同。然而，在鸟类中，UVS视觉色素通过使用一种在其他脊椎动物类别中未见的新分子机制，从祖先鸟类VS色素重新进化而来。到目前为止，在所研究的14个鸟类目中，有4个独立地发生了这种情况，尽管目前尚不清楚这种情况的适应意义。
Birds are highly visual animals with complex visual systems. In this article, we discuss the spectral characteristics and genetic mechanisms of the spectral tuning of avian visual pigments. The avian retina contains a single type of rod, four spectrally distinct types of single cone, and a single type of double cone photoreceptor. Only the single cones are thought to be involved in color discrimination; double cones are thought to be involved in achromatic visual tasks, such as movement detection and pattern recognition. Visual pigment opsin protein genes in birds are orthologous to those in other vertebrates and have a common origin early in vertebrate evolution. Mechanisms of spectral tuning in the different classes of avian cone visual pigments show similarities in most instances to those in other vertebrates. The exception is the ultraviolet/violet (SWS1) class of pigments; phylogenetic evidence indicates that the ancestral vertebrate SWSI pigment was ultraviolet sensitive (UVS), with different molecular mechanisms accounting for the generation of violet-sensitive (VS) pigments in different vertebrate classes. In birds, however, UVS visual pigments have re-evolved from an ancestral avian VS pigment by using a novel molecular mechanism not seen in other vertebrate classes. This has occurred independently in four of the 14 avian orders examined to date, although the adaptive significance of this is currently unknown.