Odeen Anders, Hart Nathan S, Håstad Olle
Department of Animal Ecology, Uppsala University, Norbyvägen 18D, Uppsala, Sweden.
J Comp Physiol A Neuroethol Sens Neural Behav Physiol. 2009 Feb;195(2):167-73. doi: 10.1007/s00359-008-0395-2. Epub 2008 Dec 2.
Recently, in vitro mutation studies have made it possible to predict the wavelengths of maximum absorbance (lambdamax) of avian UV/violet sensitive visual pigments (SWS1) from the identity of a few key amino acid residues in the opsin gene. Given that the absorbance spectrum of a cone's visual pigment and of its pigmented oil droplet can be predicted from just the lambdamax, it may become possible to predict the entire spectral sensitivity of a bird using genetic samples from live birds or museum specimens. However, whilst this concept is attractive, it must be validated to assess the reliability of the predictions of lambdamax from opsin amino acid sequences. In this paper, we have obtained partial sequences covering three of the known spectral tuning sites in the SWS1 opsin and predicted lambdamax of all bird species for which the spectral absorbance has been measured using microspectrophotometry. Our results validate the use of molecular data from genomic DNA to predict the gross differences in lambdamax between the violet- and ultraviolet-sensitive subtypes of SWS1 opsin. Additionally, we demonstrate that a bird, the bobolink Dolichonyx oryzivorus L., can have more than one SWS1 visual pigment in its retina.
最近，体外突变研究使得从视蛋白基因中几个关键氨基酸残基的身份预测鸟类紫外/紫光敏感视觉色素（SWS1）的最大吸收波长（λmax）成为可能。鉴于仅根据λmax就可以预测视锥细胞视觉色素及其色素油滴的吸收光谱，那么利用活鸟或博物馆标本的基因样本有可能预测鸟类的整个光谱敏感性。然而，尽管这个概念很有吸引力，但必须对其进行验证，以评估根据视蛋白氨基酸序列预测λmax的可靠性。在本文中，我们获得了覆盖SWS1视蛋白中三个已知光谱调谐位点的部分序列，并预测了所有已使用显微分光光度法测量光谱吸收率的鸟类的λmax。我们的结果验证了利用基因组DNA的分子数据来预测SWS1视蛋白的紫光敏感亚型和紫外光敏感亚型之间λmax的总体差异。此外，我们证明，栗胁林莺（Dolichonyx oryzivorus L.）的视网膜中可以有不止一种SWS1视觉色素。
